Method of blowing synthetic resin into a furnace

ABSTRACT

A method of blowing a synthetic resin material into a furnace comprising preparing a synthetic resin material having an average specific surface area of at least 50 m 2 /kg; and blowing the synthetic resin material from tuyeres of a shaft furnace for ironmaking.

This is a division of application Ser. No. 09/307,537 filed May 11, 1999now U.S. Pat. No. 6,085,672 which is a Division of application Ser. No.08/814,878 filed Mar. 13, 1997, now U.S. Pat. No. 5,992,335.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of blowing a synthetic resininto a furnace and an apparatus therefor.

2. Description of the Related Art

The quantity of waste synthetic resins such as plastics as industrialwaste and general garbage has recently been increasing, and disposalthereof has become an important social issue. Particularly, plastics,which is a macromolecular hydrocarbon compound, produces a highcalorific value during combustion, and cannot be disposed of in a largequantity because of damage to an incinerator upon incineration, so thatit is the current practice to dump most of waste plastics onto areclamation site for waste. However, the dumping of plastics is notdesirable from the environmental point view, and there is an increasingdemand for development of a quantity disposing method thereof.

Under such circumstances, methods using synthetic resins such asplastics as an auxiliary fuel for blast furnace are disclosed inEuropean Unexamined Patent Publication No. 0622465A1 and Japanese PatentPublication No. S51-33493. These methods comprise blowing milledsynthetic resins as a fuel into a blast furnace through tuyeres: theformer method, for example, sets forth substantial conditions of themilled synthetic resin to be blown into the furnace including a particlediameter within a range of from 1 to 10 mm and a bulk density of atleast 0.35.

As a result of repeated experiments and studies, however, the presentinventors found the existence of the following problems involved in theuse of synthetic resins such as plastics (hereinafter the descriptionwill be based on “plastics” as a typical example) as a blown fuel for ablast furnace.

Plastics rejected as industrial waste or general garbage, when viewed interms of form, are broadly divided into lumpy plastics taking a plateshape in general and film-shaped ones. The latter ones, film-shapedplastics, account for a considerable part among rejected plastics.However, because of very low transferability and fluidity of milledfilm-shaped plastics, there is a serious problem in handling when usingthem as a fuel. More specifically, when blowing plastics into a blastfurnace as a fuel, it is the usual practice to cut plastics stored in astorage silo and pneumatically feed cut plastics into the blast furnace.Because of a very low fluidity of film-shaped plastics, milled plasticscontaining much film-shaped plastics easily produce bridges(scaffolding) in the storage silo, and any problems involving inabilityto cut out milled plastics in a constant quantity from the storage silooccur frequently. Further, film-shaped plastics clog the cutting port ofthe storage silo or the interior of a pneumatic feed pipe (particularlyat bends and proximity of valves), leading to a serious problem offrequent occurrence of any problems preventing pneumatic feed to theblast furnace.

Unless these problems are overcome, therefore, it is practicallyimpossible to use film-shaped plastics as a fuel to be blown into ablast furnace or the like. In view of the present circumstances offilm-shaped plastics accounting for a major portion of waste plastics asa whole, it is clear that advantages of quantity disposal and effectiveutilization of waste plastics would be lost unless it is made possibleto use film-shaped plastics.

In order to blow plastics as a fuel into the blast furnace, furthermore,it is necessary to use milled plastics to ensure a sufficient combustionproperty. There is however a limitation on the particle diameteracceptable for milling in terms of treatment cost. A particle diameterwithin a range of from about 1 to 10 mm is therefore a limit forgranulation as is shown in the conventional art. When using lumpyplastics milled to this particle diameter, a sufficient combustionproperty may be unavailable within the blast furnace. As a result,unburned plastics adhere to each other in the bed coke, thus seriouslyimpairing permeability through the furnace, and may cause trouble in theblast furnace operation.

Milled lumpy plastics take an irregular and angular shape. Ones having aparticle diameter of from 1 to 10 mm are therefore low in dischargeproperty upon cutting out from a storage silo and in fluidity andtransferability when pneumatically feeding to the blast furnace, leadingto easy occurrence of clogging at the cutting port of silo or in themiddle of the pneumatic feed pipe system.

It is therefore very difficult to use waste plastics as a fuel to beblown into a blast furnace in an industrial scale by any of the methodsproposed by the conventional arts: simply milling plastics into aparticle diameter of from 1 to 10 mm processing the same into granuleshaving a high bulk density and blowing the same into the blast furnace.

SUMMARY OF THE INVENTION

The present invention has an object to provide a method of blowingsynthetic resins, which permits supply of waste synthetic resins as ablown fuel into a furnace, irrespective of the form thereof, and allowsimprovement of transferability and combustion property of syntheticresins supplied to the furnace, and an apparatus therefore.

To achieve the above-mentioned object, the present invention provides amethod of blowing a synthetic resin material into a furnace, comprising:

(a) a step of classifying synthetic resins into film-shaped syntheticresins and other non-film-shaped synthetic resins;

(b) a step of processing classified film-shaped synthetic resins into afirst granular resin material;

(c) a step of crushing non-film-shaped synthetic resins and processingthe same into a second granular synthetic resin material;

(d) a step of pneumatically feeding the first granular synthetic resinmaterial and the second granular synthetic material; and

(e) a step of blowing the pneumatically fed first granular syntheticmaterial and second granular resin material into a furnace.

The foregoing process of processing the film-shaped synthetic resinsinto the granular synthetic resin materials may comprise:

a step of melting or semi-melting the film-shaped synthetic resins byheat; and

a step of solidifying the film-shaped synthetic resins in a molten orsemi-molten state.

The method of blowing the synthetic resin material into the furnace ofthe present invention may further comprise:

a step of separating and removing a chlorine-containing macromolecularresin material from the film-shaped synthetic resins, the film-shapedsynthetic resins after separation and removal of the chlorine-containingmacromolecular resin material being processed into a granular syntheticresin material in step (b); and

a step of separating and removing the chlorine-containing macromolecularresin material from the non-film-shaped synthetic resins, the separationand removal step being carried out after step (c)

In the method of the present invention, the classifying step, the stepof processing the film-shaped synthetic resins and the step ofprocessing the non-film-shaped synthetic resins may be as follows:

the classifying step may comprise classifying the synthetic resins intoa film-shaped synthetic resin material, a solid synthetic resin materialand a sheet-shaped synthetic resin material, the sheet-shaped resinmaterial being an intermediate form between the film-shaped syntheticresin material and the solid synthetic resin material;

the step of processing the film-shaped synthetic resins may comprise: astep of crushing the film-shaped synthetic resin material into smallfilm pieces; and a step of applying a melting andsolidification/granulating treatment to the small film pieces, therebypreparing first synthetic resin particles;

the step of processing the non-film-shaped synthetic resins maycomprise:

a step of crushing the solid synthetic resin material,

thereby preparing second synthetic resin particles;

a step of crushing the sheet-shaped synthetic resin material,

thereby preparing small sheet pieces having a maximum size smaller thanthe maximum size of the small film pieces; and

a step of supplying a melting and solidification/granulating treatmentto the small sheet pieces,

thereby preparing third synthetic particles.

Further, the process of processing the non-film-shaped synthetic resinsmay comprise:

a step of supplying shredder dust produced during rejection of anautomobile or a home electrical appliance;

a step of cutting or crushing the shredder dust;

a step of heating the crushed shredder dust to semi-melt or melt thesame; and

a step of causing the semi-molten or molten shredder dust to contractand solidify into a granular form.

Blowing of the granular synthetic resin material into the furnace shouldpreferably be accomplished by blowing the granular synthetic resinmaterial having such a particle diameter as giving a terminal velocityhigher than the flow velocity of gases discharged from the combustionzone formed at the tuyere nose in the lower part of the furnace.

The present invention further provides an apparatus for blowing asynthetic resin material into a furnace, comprising:

a first processing line for processing film-shaped synthetic resins intoa granular synthetic resin material;

the first processing line comprising a granulating/solidifying unit forprocessing the film-shaped synthetic resins into the granular syntheticresin material through solidification after melting or semi-melting thesame with heat;

a second processing line for processing non-film-shaped synthetic resinsinto the granular synthetic resin material;

the second processing line comprising a crushing unit crushing thenon-film-shaped synthetic resins;

a primary storage silo for storing the granular synthetic resin materialobtained in the first processing line and the second processing line;

a blowing station for pneumatically supplying the granular syntheticresin material supplied from the primary storage silo into the furnace;and

the blowing station comprising:

a secondary storage silo for storing the granular synthetic resinmaterial supplied from the primary storage silo;

a blowing tank for receiving the granular synthetic resin materialsupplied from the secondary storage silo,

and pneumatically feeding the same to the furnace;

and

means for continuously supplying the granular synthetic resin materialfrom the blowing tank into a blowing port of the furnace.

Further, the apparatus of the present invention should preferably havethe following components:

a separating unit for separating and removing chlorine-containingmacromolecular resin materials from the film-shaped synthetic resins,arranged in the upstream of the granulating/solidifying unit in thefirst processing line; and

a separating unit for separating and removing chlorine-containingmacromolecular resin materials from the non-film-shaped syntheticresins, arranged in the downstream of the crushing unit in the secondprocessing line.

The present invention further provides a method of blowing syntheticresin material into a furnace, comprising:

a step of preparing a synthetic resin material having an averagespecific surface area of at least 50 m²/kg; and

a step of blowing the synthetic resin material from tuyeres of a shaftfurnace for ironmaking.

It suffices for the synthetic resin material to contain at least 5 wt. %particles having a particle diameter of up to 1 mm and having an averagespecific surface area of at least 25 m²/kg.

The synthetic resin material may contain at least 3 wt. % particles of afoaming substance and having an average specific surface area of atleast 20 m²/kg.

The present invention furthermore provides a method of blowing asynthetic resin material into a furnace, comprising:

(a) a step of determining the heat value of a synthetic resin materialfrom the result of quality determination of the material when it ispossible to determine quality of the synthetic resin material and mixingof impurities is not observed;

(b) a step of determining the heat value of a synthetic resin materialby measuring by an usual measuring method when it is possible todetermine quality of the synthetic resin material and mixing ofimpurities is observed;

(c) a step of determining the heat value of a synthetic resin materialby measuring by an usual measuring method when it is impossible todetermine quality of the synthetic resin material;

(d) a step of blending two or more kinds of synthetic resin materialswith the use of heat values for these two or more kinds of syntheticresin materials as determined in steps (a) to (c) so as to give aprescribed heat value of a mixture comprising the two or more kinds ofsynthetic resin materials; and

(e) a step of blowing the blended synthetic resin materials from tuyeresof the furnace.

The method of charging a synthetic resin material into a furnace of thepresent invention comprises:

(a) a step of preparing a synthetic resin material as a blast furnaceburden raw material;

(b) a step of preparing a granular sinter as a blast furnace burden rawmaterial;

(c) a step of preparing a mixture of the synthetic resin material andthe granular sinter; and

(d) a step of charging the mixture into an intermediate zone between thecenter and the wall of the blast furnace.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating an embodiment of the fuel blowingmethod of the present invention;

FIG. 2 is a schematic diagram illustrating a configuration of a methodfor causing contraction, solidification and granulation of syntheticresins (A);

FIG. 3 is a schematic diagram schematically illustrating the principleof another method for causing contraction, solidification andgranulation of the synthetic resins (A);

FIG. 4 is a schematic diagram illustrating another configuration of thestorage method of a granular synthetic resin material in the flowchartshown in FIG. 1;

FIG. 5 is a graph comparing a granular synthetic resin material (a)obtained through contraction, solidification and granulation of afilm-shaped synthetic resin material by a specific method and a granularsynthetic resin material (b) obtained through a milling treatment of alumpy synthetic resin material, in terms of the mixing ratio, cokesubstitution ratio and frequency of occurrence of supply any problems;

FIG. 6 is a graph the relationship between the angle of rest and thefrequency of occurrence of supply any problems for a granular syntheticresin material obtained through a milling treatment of a lumpy syntheticresin material by different values of bulk density;

FIG. 7 is a schematic diagram illustrating the construction of a scrapmelting experimental furnace used in embodiments;

FIG. 8 is a schematic diagram illustrating the construction of acombustion burner provided at a tuyere portion of the scrap meltingexperimental furnace of FIG. 7;

FIG. 9 is a flowchart illustrating an embodiment of the fuel blowingmethod of the present invention;

FIG. 10 is a schematic diagram illustrating a typical construction of aseparator of a chlorine-containing macromolecular resin material;

FIG. 11 is a schematic diagram illustrating another typical constructionof the separator of a chlorine-containing macromolecular resin material;

FIG. 12 is a flow sheet illustrating an embodiment of the presentinvention;

FIG. 13 is a schematic diagram illustrating the functions of themelting/solidification/granulation unit;

FIG. 14 is a schematic diagram illustrating the principle of granulationof small synthetic resin pieces by themelting/solidification/granulation unit shown in FIG. 13;

FIG. 15 is a flow sheet of a pneumatic feeding equipment for blowinggranulated synthetic resin particles to a blast furnace;

FIG. 16 is a flow sheet illustrating another embodiment of the presentinvention;

FIG. 17 is a flow sheet illustrating further another embodiment of thepresent invention;

FIG. 18 is a flow diagram illustrating an example of treatment ofshredder dust in a shaft furnace in the present invention;

FIG. 19 is a schematic diagram illustrating a method of causingcontraction and solidification for granulation of fine dust by amilling/rapid cooling unit;

FIG. 20 is a schematic diagram of a method for granulating dust aftercontraction and solidification by the milling unit;

FIG. 21 is a schematic diagram illustrating method for causingcontraction and solidification for granulation of fine dust by aheating/rapid cooling unit;

FIG. 22 is a schematic perspective view of the interior of a shaftfurnace for illustrating the combustion zone formed at tuyere nose ofthe shaft furnace used for application of the present invention;

FIG. 23 is a schematic longitudinal sectional view illustrating atypical shaft furnace combustion experimental equipment used forapplication of a combustion test in the present invention;

FIG. 24 is a graph illustrating the relationship between therepresentative particle diameter of the synthetic resin material and thedegree of burn-up of the synthetic resin material in the case where thecombustion experimental equipment shown in FIG. 23 is used;

FIG. 25 is a graph illustrating the relationship between the verticalgas flow velocity at the terminal of the combustion zone and the degreeof burn-up of the synthetic resin material in the case where thecombustion experimental equipment shown in FIG. 23 is used;

FIG. 26 is a schematic diagram illustrating an embodiment of theapparatus for blowing a synthetic resin material into a furnace of thepresent invention;

FIG. 27 is a schematic diagram illustrating another embodiment of theapparatus for blowing a synthetic resin material into a furnace of thepresent invention;

FIG. 28 is a schematic diagram illustrating an embodiment of agranulating/solidifying unit in the apparatus shown in FIG. 26 or 27;

FIG. 29 is a schematic diagram illustrating another embodiment of thegranulating/solidifying unit in the apparatus shown in FIG. 26 or 27;

FIG. 30 is a schematic diagram schematically illustrating the principleof contraction/solidification/granulation of synthetic resins by theunit shown in FIG. 29;

FIG. 31 is a schematic diagram illustrating another configuration of theblowing station in the apparatus shown in FIG. 26 or 27;

FIG. 32 is a schematic diagram illustrating further anotherconfiguration of the blowing station in the apparatus shown in FIG. 26or 27;

FIG. 33 is a schematic diagram illustrating an embodiment of theseparator in the apparatus shown in FIG. 32;

FIG. 34 is a schematic diagram illustrating another embodiment of theseparator in the apparatus shown in FIG. 32;

FIG. 35 is a schematic diagram illustrating another embodiment of thestorage silo in the apparatus shown in FIG. 26 or 27;

FIG. 36 is a schematic diagram partially illustrating an embodiment ofthe apparatus for blowing a synthetic resin material into a furnace ofthe present invention;

FIG. 37 is a schematic diagram partially illustrating an embodiment ofthe apparatus for blowing a synthetic resin material into a furnace ofthe present invention;

FIG. 38 is a schematic diagram partially illustrating an embodiment ofthe apparatus for blowing a synthetic resin material into a furnace ofthe present invention;

FIG. 39 is a schematic diagram partially illustrating another embodimentof the apparatus for blowing a synthetic resin material into a furnaceof the present invention;

FIG. 40 is a schematic diagram illustrating an embodiment of the presentinvention;

FIG. 41 is a schematic longitudinal sectional view illustrating a shaftfurnace combustion experimental apparatus used for application of acombustion test in the present invention;

FIG. 42 is a flowchart illustrating the relationship between materialdetermination and impartment of a heat value for the synthetic resinmaterial to be blown into a metallurgical furnace in the presentinvention;

FIG. 43 is a flow sheet which illustrates a typical layout for blowing asynthetic resin material into a metallurgical furnace in the presentinvention;

FIG. 44 is a schematic diagram illustrating the method of the presentinvention;

FIG. 45 is a schematic longitudinal sectional view of the furnace top ofthe blast furnace, illustrating a state in which a mixture of a wastesynthetic resin material and fine granular sinter is charged onto thesurface of the ore layer, showing an embodiment of the presentinvention;

FIG. 46 is a graph illustrating the distribution of gas flow velocity inthe furnace radial direction for each of the cases with and without themixture in the intermediate zone charged from the furnace top;

FIG. 47 is a distribution curve of the ore reduction ratio in thefurnace height direction during operation for each of the cases with andwithout the mixture in the intermediate zone charged from the furnacetop;

FIG. 48 is a graph illustrating the relationship between the longerdiameter of a waste synthetic resin material and splash ratio for eachlevel of the ratio of the waste synthetic resin material; and

FIG. 49 is a graph illustrating the relationship between the chargingposition of the mixture in the furnace radial direction and the splashratio f.

DESCRIPTION OF THE EMBODIMENTS

Embodiment 1

Based on the preceding knowledge that the presence of film-shapedsynthetic resin materials mixed in waste synthetic resins makes itsubstantially impossible to make use of synthetic resins as furnacefuel, the fuel blowing method of the present invention is characterizedfundamentally by accepting synthetic resins to be used for fuel into aprocessing facility in the state that the synthetic resins areclassified into synthetic resins comprising principally film-shapedsynthetic resins and other synthetic resins, processing themrespectively into granular matters suited to pneumatically feeding solidfuel by different steps and pneumatically feeding these processedgranular synthetic resins into a furnace.

In particular, with respect to film-shaped synthetic resins, it has beenfound that, when processed by a specific method, granular syntheticresin materials which are very excellent in fluidity, carrying propertyand combustibility are obtained and that blending such granularsynthetic resin materials with pulverized matters such as massivesynthetic resin materials can enhance notably the fluidity, the carryingproperty and the combustibility of the whole synthetic resin materials,and a fuel blowing method constituted on the basis of this knowledge isanother characteristic of the present invention.

Further, particularly from the viewpoint of securing thedischargeability of granular synthetic resin materials from a storagesilo and the carrying property thereof in a pneumatically feeding pipeat high levels, it has been found that it is essential to cause therepose angle of the granular synthetic resin materials to fall in arange of a specific value, and a fuel-blowing method constituted on thebasis of such knowledge is still another characteristic of the presentinvention.

FIG. 1 is a flow chart showing one example of the fuel blowing method ofthe present invention, and the present invention shall be explainedbelow based on this flow chart.

In the present invention, synthetic resins to be used for fuel areaccepted into a processing facility in the state that the syntheticresins are classified into synthetic resins (A) comprising principallyfilm-shaped synthetic resins and other synthetic resins (B) (that is,comprising principally massive synthetic resin materials). In thisconnection, synthetic resin materials of other forms which are inferiorin fluidity and carrying property, for example, foamed plastics, as wellas the film-shaped synthetic resin materials can be contained in thesynthetic resins (A).

The film-shaped synthetic resin materials shall not specifically berestricted, but according to what have been confirmed by the presentinventors through experiments, synthetic resin films having a thicknessof 100 μm or less are particularly inferior in fluidity and carryingproperty, and therefore the synthetic resin films having a thickness of100 μm or less are classified preferably into-the synthetic resins (A)in a classifiable limit. It is a matter of course, however, that theyshall not necessarily be restricted to such classification standard.Further, such relatively thick synthetic resins as used for so-calledPET bottles as well as very thin films such as polyethylene films can becontained in the synthetic resins (A). Whether or not they areclassified into the synthetic resins (A) is determined according tofactors such as the compositions, materials (for example, the materialsother than synthetic resins are contained or not contained as compositematerials) and the forms of the synthetic resins as well as thethicknesses thereof.

On the other hand, the synthetic resins (B) comprise principally massivesynthetic resin materials such as plates, but it is a matter of coursethat they shall not be restricted thereto.

In short, considering the fluidity and the carrying property ofsynthetic resins collected, synthetic resins which are extremelyinferior in fluidity and carrying property in the state that they arecrushed, such as at least polyethylene films can be classified into thesynthetic resins (A), and synthetic resins such as massive plasticshaving better fluidity and carrying property than those of the aboveresins can be classified into the synthetic resins (B). The othersynthetic resins can be classified into either of the synthetic resins(A) and (B) considering the fluidity and the carrying property.

From the viewpoint of the whole conversion-to-fuel system, there is noneed to strictly classify all of the film-shaped synthetic resinmaterials out of the synthetic resins to be supplied as fuel into thesynthetic resins (A), and all of the massive synthetic resins into thesynthetic resins (B), respectively. Considering the quality thereof aswaste, such strict classification is practically difficult. Accordingly,it is allowable that there are contained to some extent, massivesynthetic resin materials in the synthetic resins (A), and film-shapedsynthetic resin materials in the synthetic resins (B).

In FIG. 1, X represents a processing line for the synthetic resins (A)comprising principally the film-shaped synthetic resin materials, and Yrepresents a processing line for the synthetic resins (B) comprisingprincipally the massive synthetic resin materials. In the processingline X, the synthetic resins (A) are molten or semi-molten by heat andthen solidified, whereby they are processed into a volume-reduced andsolidified (volume-reduced=reduced in volume) granular synthetic resinmaterial (a). Meanwhile, in the processing line Y, the synthetic resins(B) are pulverized and processed into a granular synthetic resinmaterial (b).

In the processing line X, the synthetic resins (A) are crushed (orroughly crushed), if necessary, by means of a crusher 1 and then chargedinto a granulation and solidification equipment 2 by means of a conveyorcarrier, in which they are processed into the volume-reduced andsolidified granular synthetic resin material (a). Iron scraps mixed inthe synthetic resins are removed by means of a magnetic separator (anapparatus in which iron scraps are adsorbed on a magnet to remove them)in the middle of the conveyor carrier described above. If the syntheticresins (A) are crushed by means of the granulation and solidificationequipment 2 described later, crushing by means of the crusher 1described above is not necessarily required. Accordingly, in such case,the crusher 1 may not be installed.

In the granulation and solidification equipment 2, the volume-reducedsolidification—granulation of the synthetic resins (A) is carried out byany of the following methods [1] to [3] to obtain the granular syntheticresin material (a): [1] a method in which after melting the syntheticresins (A) by heating, they are cooled down and solidified, and thissolidified synthetic resin material is cut or pulverized, [2] a methodin which the synthetic resins (A) are cut or crushed (this cutting orcrushing may be carried out by means of the crusher 1 described aboveinstead of the granulation and solidification equipment); this cut orcrushed synthetic resin material is semi-molten by heating or frictionalheat generated by the cutting or crushing described above; thesemi-molten synthetic resin material is contracted and solidified byrapidly cooling, wherein the synthetic resin material is contracted andsolidified into a granular form, or the contracted and solidifiedsynthetic resin material is pulverized, to thereby obtain the granularsynthetic resin material (a), and [3] a method as one embodiment of themethod [2] described above, in which the synthetic resins (A) are cut orcrushed by means of rotary blades which are rotated at a high speed, andthe synthetic resins are semi-molten by frictional heat generated by theabove cutting or crushing; then, this semi-molten synthetic resinmaterial is contracted and solidified by rapidly cooling by sprayingwater, wherein the synthetic resin material is contracted and solidifiedinto a granular form or contracted and solidified and immediatelycrushed by means of the rotary blades described above to thereby obtainthe granular synthetic resin material (a).

Among these methods, a typical example of the method [1] is a method inwhich after completely molting the synthetic resins (A) and molding thisinto strings by extruding with an extruding machine, they are cut into agranular form, whereby the granular synthetic resin material (a) isobtained. In addition to the above methods, various processing methodscan be employed.

In contrast with this, the methods [2] and [3] are methods in which thesynthetic resins (A) are contracted and solidified by semi-meltingwithout completely melting and then rapidly cooling by spraying water,wherein the synthetic resins (A) are contracted and solidified into agranular form, or the contracted and solidified synthetic resins (A) arepulverized into a granular form, whereby the granular synthetic resinmaterial (a) is obtained. The present inventors have found that thegranular synthetic resin material (a) obtained by the methods [2] and[3] (particularly the method [3] shows very excellent fluidity andcarrying property as compared with not only those of the pulverizedmatters of the film-shaped synthetic resin materials but also those ofthe pulverized matters of the massive synthetic resin materials and isvery excellent as well in combustibility and that the carrying propertyand the combustibility of the whole synthetic resins can notably beraised by using them in a mixture with the pulverized matters of themassive synthetic resin materials. Accordingly, in the fuel blowingmethod of the present invention, granular contraction and solidificationor contraction and solidification—granulation of the synthetic resins(A) is most preferably carried out by the method [2] or [3] in thegranulation and solidification equipment 2 to obtain the granularsynthetic resin material (a).

FIG. 2 shows one structural example for continuously carrying outgranular contraction and solidification or contraction andsolidification—granulation by the method [2] described above. Thesynthetic resins (A) charged into the granulation and solidificationequipment 2 are crushed by means of a crushing equipment 12 and thencharged into a volume-reduction and solidification equipment 13. In thisvolume-reduction and solidification equipment 13, the synthetic resins(A) are carried into a heating chamber 15 and subsequently a coolingchamber 16 by means of a carrying device (carrier belt and the like). Inthe heating chamber 15, the synthetic resins become semi-molten byheating (gas heating, indirect gas heating or electric heating) and thenrapidly cooled down in the cooling chamber 16 by spraying water to becontracted and solidified. In this case, the synthetic resins (A) can becontracted and solidified into a granular form by suitably selecting thecrushing form of the synthetic resins (A) and the charging state thereofinto the heating chamber, and therefore according to this method, thegranular synthetic resin material (a) is obtained by contraction andsolidification.

On the other hand, in a method in which a part or all of the syntheticresins is not contracted and solidified into a granular form, thecontracted and solidified synthetic resins are charged into a millingequipment 14 from the volume-reduction solidification equipment 13 andmilled into a granular form by means of this milling equipment, wherebythe granular synthetic resin material (a) is obtained.

The granular synthetic resin material (a) obtained in the mannersdescribed above has been obtained by contracting and solidifying thecrushed film-shaped synthetic resin materials into a granular in asemi-molten state, or milling the synthetic resin materials aftercontracting and solidifying them. Accordingly, it has a relativelyporous property as compared with the crushed matters of the massivesynthetic resin materials and has a large specific surface area. Inaddition, it does not have an angular form as is the case with thecrushed matters of the massive synthetic resin materials and has aroundish form on the whole. Accordingly, it shows excellentcombustibility and fluidity.

FIG. 3 shows schematically the principle of granular contraction andsolidification or contraction and solidification—granulation carried outby the method (3), wherein the synthetic resins (A) are cut or crushedby means of a rotary blade 18 which is rotated at a high rate, and thesynthetic resin material is semi-molten by frictional heat generated bythis cutting or crushing; then, this semi-molten synthetic resinmaterial is contracted and solidified by rapidly cooling down from thetemperatures described above by spraying water, wherein the semi-moltensynthetic resin material is contracted and solidified into a granularform, or contracted and solidified and immediately crushed by means ofthe rotary blade 18 described above to thereby obtain the granularsynthetic resin material (a). In this method, all of crushing (orcutting) of the synthetic resin materials, semi-melting and millingthereof (provided that milling is not required when the synthetic resinmaterials are contracted and solidified into a granular form by cooling)after contraction and solidification are carried out in a batch systemby means of the rotary blade 18 rotating at a high rate. Accordingly, aseries of processing steps of “crushing (orcutting)→semi-melting→granular contracting and solidifying by rapidlycooling” or “crushing (or cutting)→semi-melting→granular contracting andsolidifying by rapidly cooling→milling” is quickly carried out for shorttime. In addition, the synthetic resin materials are semi-molten duringcrushing (cutting) by the rotary blade 18 and stirring at a high rate,and rapid cooling from such state is quickly carried out. Accordingly,the granular synthetic resin material (a) which is more preferred interms of a specific surface area and a grain form is obtained. Further,crushing (or cutting), semi-melting and milling after contracting andsolidifying are carried out only by the action of the rotary blade 18,and therefore this system is advantageous in terms of facility cost andoperation cost.

Also in the method (3) described above, the synthetic resins (A) can becontracted and solidified into a granular form by suitably selecting thecrushing form of the synthetic resins and the form of charging themagainst the rotary blade, and therefore according to this method, thegranular synthetic resin material (a) which has been contracted andsolidified can be obtained substantially without milling by means of therotary blade after contraction and solidification. On the other hand, ina method in which apart or all of the synthetic resin material is notcontracted and solidified into a granular form, the granular syntheticresin material (a) is obtained by milling by means of the rotary bladeas described previously,

In the methods [2] and [3], temperatures for semi-melting the syntheticresins (A) varide to some extent according to the kinds in forms of thesynthetic rasins. From the view point only of, for example, thematerials, the temperatures reside in a level of 105 to 115° C. in thecase of low density polyethylene and are about 128° C. in the case ofmedium low density polyethylene. Accordingly, the temperatures forsemi-solidifying the synthetic resins (A) are suitably selectedaccording to the kinds, the proportion and the forms of synthetic resinmaterials contained in the synthetic resins (A).

The granular synthetic resin material (a) thus obtained is sieved bymeans of a sieving equipment 3, and only grains having a prescribedgrain diameter (for example, −6 mm) or less are sent to a storage silo 9via a path 19. In this constitutional example, the path 19 isconstituted by a pneumatically feeding pipe (in the drawing, 10 is anair blower), and the granular synthetic resin material (a) ispneumatically fed (pneumatic transportation, hereinafter the same shallapply) to the storage silo 9. On the other hand, the granular syntheticresin material having a grain diameter exceeding the prescribed graindiameter is returned to a carrying line present at the inlet side of thegranulation and solidification equipment 2 via a path 20 (in thedrawing, 10 is an air blower) which is a pneumatic feeding pipe andrecharged into the granulation and solidification equipment 2 togetherwith the synthetic resins (A). A position to which this coarselygranulated synthetic resin material is sent back is optional, and it canbe sent back to respective positions (usually, a transporting line) suchas, for example, between the granulation and solidification equipment 2and the magnetic separator 4, and the inlet side of a crusher 1. In somecase, it can be supplied as well to the processing line Y. When it issupplied to this processing line Y, it can be supplied to respectivepositions (usually, a transporting line) such as, for example, the inletside of a primary crusher 5, between the primary crusher 5 and asecondary crusher 6, between the secondary crusher 6 and a classifier 7and between the classifier 7 and a crusher 8. In addition to the above,the coarsely granulated synthetic resin material may be taken out of thesystem and charged directly into other steps (for example, charged intothe tops of a blast furnace and a scrap melting furnace or chargeddirectly into a coke oven and a sintering furnace).

On the other hand, in the processing line Y, the synthetic resins (B)are coarsely crushed (for example, crushed to a grain diameter of about50 mm) by means of the primary crusher 5 and then charged into thesecondary crusher 6 by conveyor carrying to be secondarily crushed (forexample, crushed to a grain diameter of about 20 mm). The primarilycrushed synthetic resins (B) are subjected to removal of iron scrapsmixed therein by means of the magnetic separator 4 (an equipment foradsorbing iron scraps on a magnet to remove them) in the middle of theconveyor carrying described above.

The secondarily crushed synthetic resins (B) are charged into theclassifier 7 by conveyor carrying, wherein foreign matters such asmetals, earth and sand, and stones are separated and removed by a methodsuch as wind classification. Then, they are sent to the crusher 8(tertiary crusher) via a path 21 a and crushed into a prescribeddiameter (for example, −6 mm) or less, whereby the granular syntheticresin material (b) is obtained. This granular synthetic resin material(b) is sent to a storage silo 9 via a path 21 b. In this constitutionalexample, the paths 21 a, 21 b are constituted by pneumatically feedingpipes (in the drawing, 10 is an air blower), and the granular syntheticresin material (b) is pneumatically fed into the storage silo 9.

The mixture of the granular synthetic resin materials (a) and (b) storedin the storage silo 9 is carried by a conveyor or pneumatically fed intoa pneumatically feeding facility 11 comprising a blowing tank and thelike and pneumatically fed into a furnace such as a blast furnace viathis pneumatically feeding facility 11. Then, the mixture is blown intothe furnace through the tuyere thereof.

In the constitutional example shown in FIG. 1, the magnetic separator 4is provided each at one portion in the processing lines X and Y,respectively, but the magnetic separators 5 maybe disposed at pluralportions in the respective processing lines X and Y.

The crushing systems of various crushing equipments (including themilling equipment 8 ) disposed in the processing lines X and Y areoptional. In addition to a crushing system carried out only byconventional mechanical means, there can be applied as well, forexample, a so-called freeze-crushing system in which matters to beprocessed are crushed in a frozen state.

Usually, auxiliary facilities such as a yard drying facility forsynthetic resins carried in are provided at the inlet side of theprocessing facilities shown in FIG. 1.

As described previously, the amounts of the synthetic resins (A)comprising principally the film-shaped synthetic resin materials and theother synthetic resins (B) which are fed to the processing facilitiesare dispersed to some extent according to the lapse of time in certaincases due to the properties of wastes. In the case of limiting the timeto a relatively short period (for example, several hours to some tenhours), only either one kind of the synthetic resins is supplied, andtherefore it is possible that the synthetic resins processed andpneumatically fed into a furnace is tentatively limited only to eitherone of the synthetic resins (A)—the granular synthetic resin material(a) and the synthetic resins (B)—the granular synthetic resin material(b). Also, it is possible that only either one of the granular syntheticresin material (a) and the granular synthetic resin material (b) ispneumatically fed tentatively into the furnace because of reasons otherthan the above one. Further, the granular synthetic resin materials (a)and (b) can be stored in different silos to be pneumatically fed intothe furnace via separate paths.

As described previously, the granular synthetic resin material (a)obtained by carrying out granular contraction and solidification orcontraction and solidification—granulation has a relatively porousproperty and a large specific surface area. In addition thereto, sincethe granular synthetic resin material (a) has a roundish form on thewhole, it shows excellent combustibility and fluidity, and thecombustibility, the fluidity and the carrying property of the wholegranular synthetic resin materials supplied to a furnace can effectivelybe raised by mixing the granular synthetic resin material (a) with thegranular synthetic resin material (b). That is, with respect to thecombustibility, when the mixture of the granular synthetic resinmaterial (a) and the granular synthetic resin material (b) is blown intothe furnace, the granular synthetic resin material (a) having a goodcombustibility burns rapidly to ignite quickly the granular syntheticresin material (b), and this increases markedly the combustibility ofthe whole granular synthetic resin materials blown into the furnace.

Further, also with respect to the fluidity and the carrying property, alubricant function which enhances the fluidity of the whole granularsynthetic resin materials is displayed by causing the granular syntheticresin material (a) which has a roundish form and is excellent influidity and carrying property to be contained in the granular syntheticresin materials. As a result thereof, the fluidity and the carryingproperty of the whole granular resin materials are improved to a largeextent.

In order to obtain the function described above, the granular syntheticresin material (a) is preferably mixed with the granular synthetic resinmaterial (b) in a proportion (a)/[(a)+(b)] of 0.10 or more in terms of aweight ratio. FIG. 5 shows the relation of the weight ratio (a)/[(a)+(b)] with the carrying property (feeding trouble-generatingfrequency) and the combustibility (rate of substituting coke with blownfuel) of the mixture, wherein the granular synthetic resin material (a)having a grain diameter of 6 mm or less obtained by subjecting thefilm-shaped synthetic resin material to contraction andsolidification—granulation processing by the method [3] is mixed withthe granular synthetic resin material (b) (repose angle of both granularsynthetic resin materials: 40°) having a grain diameter of 6 mm or lessobtained by subjecting the massive synthetic resin material to millingprocessing in various ratios, and this mixture is pneumatically fed intothe tuyere of a blast furnace and blown into the furnace. The feedingtrouble-generating frequency and the rate of substituting coke withblown fuel have been determined in the following manners:

(i) Feeding Trouble-generating Frequency

A feeding trouble-generating frequency index observed when only thegranular synthetic resin material (b) (repose angle: 40°) having a graindiameter of 6 mm or less obtained by subjecting the massive syntheticresin materials to milling processing is fed alone into the furnace isset at “1”, and a feeding trouble-generating frequency compared withthis case has been shown by an index. With respect to the presence offeeding trouble generation, a change in the weight of the granular resinmaterials in a storage silo is always watched, and when a state of nochange in weight has been continued for prescribed time (for example,about 10 minutes), any problems (clogging caused at the exit of a siloand in the middle of a pneumatically feeding pipe) have been judged tobe caused.

(ii) Coke substitution rate

Coke substitution rate=(ratio of coke reduced by blowing granularsynthetic resin material)/(blown ratio of granular synthetic resinmaterial)

wherein:

the ratio of coke reduced by blowing granular synthetic resin material:kg/t·pig,

blown ratio of granular synthetic resin material: kg/t·pig.

It can be found from FIG. 5 that the excellent combustibility andcarrying property are obtained in an area where the ratio (a)/[(a)+(b)]is 0.10 or more.

As described above, in order to control the ratio (a)/[(a)+(b)] in aprescribed range, it is preferred to once store the granular syntheticresin material (a) and the granular synthetic resin material (b) in therespective storage silos and then blend them. A constitutional exampleof the storage silo therefor is shown in FIG. 4, wherein the granularsynthetic resin material (a) and the granular synthetic resin material(b) are stored in respective primary storage silos 22, 23; and thegranular synthetic resin material (a) and the granular synthetic resinmaterial (b) are suitably delivered from these primary storage silos 22,23 to a secondary storage silo 24 (corresponding to the storage silo 9shown in FIG. 1) to store the granular synthetic resin materials havingthe controlled ratio (a)/[(a)+(b)] in the secondary storage silo 24.

In addition to the constitution described above, there maybe taken aconstitution in which the granular synthetic resin material (a) and thegranular synthetic resin material (b) each stored in the primary storagesilos 22, 23 are blended directly in the pneumatically feeding pipeline.

Further, the granular synthetic resin materials (a) and (b) arepreferably processed into the resin materials having a bulk density of0.30 or more and a repose angle of 40° or more. As described previously,it has been proposed in conventional techniques to set the bulk densityof milled synthetic resin materials to 0.35 or more. In particular,there is the problem that an increase in the bulk density of milledmassive synthetic resin materials increases (shortens the life of acrushing blade) a load in a crusher, and therefore some crushers giveonly crushed resin materials having a bulk density of less than 0.35. Onthe other hand, investigations made by the present inventors have madeit clear that if the synthetic resin materials have a bulk density of0.30 or more, problems including pressure loss shall not be caused inpneumatically feeding the granular synthetic resin materials, and thegeneration of any problems such as bridging (hanging) of the syntheticresin materials in the storage silos and clogging at a bent pipe part ina pneumatically feeding pipe line and in the circumference of valves isscarcely related to the bulk density of the granular synthetic resinmaterials and depends largely on the grain form of the granularsynthetic resin materials and that an effect for suppressing thegeneration of the any problems described above based on this grain formis explainable by the repose angle of the granular synthetic resinmaterials.

FIG. 6 shows the relation of the repose angles of the granular syntheticresin materials having grain diameters of 6 mm or less obtained bysubjecting the massive synthetic resin materials to milling processingwith a generating frequency of feeding any problems such as bridging(hanging) in the storage silos and clogging in the pneumatically feedingpipes by granular synthetic resin materials each having a different bulkdensity. The feeding trouble-generating frequency was evaluated in thesame manner as in FIG. 5.

It can be found from FIG. 6 that such feeding any problems as describedabove can suitably be prevented by setting the repose angles to 40° C.or less regardless of the bulk density of the granular synthetic resinmaterials.

Further, it has been found that with respect to the granular syntheticresin materials obtained by carrying out granular contraction andsolidification or contraction and solidification—granulation by themethods [2] and [3] out of the granular synthetic resin materials (a),the granular synthetic resin materials having a repose angle of 40° orless can be obtained only by carrying out granular contraction andsolidification or contraction and solidification—granulation by theabove methods. On the other hand, with respect to the granular syntheticresin material (a) obtained by carrying out volume-reduction andsolidification—granulation by the method [1] described previously or thegranular synthetic resin material (a) obtained by carrying outcontraction and solidification—granulation by a method other than themethods [1] to [3] described previously, and the granular syntheticresin material (b) obtained by subjecting the synthetic resins (B) tocrushing processing, crushing systems and the like are suitably selectedin order to achieve the repose angle of 40° or less.

The grain diameters of the granular synthetic resin materials (a) and(b) obtained by processing in the present invention are set preferablyto 10 mm or less, more preferably 4 to 8 mm from the viewpoint of thecombustibility.

The fuel blowing method of the present invention can be applied tovarious furnaces including a blast furnace and a rotary kiln.

Targets for processing in the present invention are synthetic resinswhich are essentially wastes (including wastes as so-called dusts, andscraps and defectives coming out of factories in manufacturing andprocessing). Accordingly, synthetic resins which foreign matters(metals, paper, and other inorganic and organic matters) other thansynthetic resins are adhered to or mixed in can be targeted. Specificexamples of such waste synthetic resins include plastic bottles, plasticbags, plastic packagings, plastic films, plastic trays, plastic cups,magnetic cards, magnetic tapes, IC cards, flexible containers, printedcircuit boards, printed sheets, cable-covering materials, bodies andframes for business equipment or home electric appliances, cosmeticplywoods, pipes, hoses, synthetic fibers and clothings, plastic moldingpellets, urethane materials, packaging sheets, packaging bands,packaging cushion materials, electric parts, toys, stationeries, toners,car parts, (for example, interior products and bumpers), shredder dustscoming from automobiles and home electric appliances, ion exchangeresins, synthetic papers, synthetic resin adhesives, synthetic resinpaints, and solidified fuels (waste plastic volume-reduced matters).

It is a matter of course that among synthetic resins carried intoprocessing facilities as wastes, synthetic resins which are alreadygranular and therefore can pneumatically be fed into a furnace as theyare (for example, ion exchange resins which are granular, syntheticresin pellets for molding, synthetic resin spheres for toys and thelike) can be fed into a furnace in such a manner as charging into astorage silo as they are.

EXAMPLES Example 1

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into a processing and blowingfacility for synthetic resins shown in the flow chart of FIG. 1 in theproportions of 2.5 t/hr and 5 t/hr respectively to process them into thegranular synthetic resin materials (a) and (b). After blending them in astorage silo, they were pneumatically fed into a blast furnace via apneumatically feeding pipe line and blown into the furnace from thetuyere together with powdered coal. The processing and feedingconditions of the synthetic resins and the operating conditions of theblast furnace are shown below. ps (i) Processing Conditions of theSynthetic Resins

(i-1) Synthetic Resins (A)

The synthetic resins were roughly crushed according to the flow chart ofFIG. 1 and then subjected to contraction and solidification—granulationprocessing by the method [3] described previously to process them intothe granular synthetic resin material (a) having a grain diameter of 6mm or less, and this was transferred into a storage silo.

(i-2) Synthetic Resins (B)

The synthetic resins were subjected to primary crushing, secondarycrushing and milling processing according to the flow chart of FIG. 1 toprocess them into the granular synthetic resin material (b) having agrain diameter of 6 mm or less, and this was transferred into thestorage silo.

(ii) Conditions for Pneumatically Feeding the Granular Synthetic ResinMaterials

The mixture of the granular synthetic resin materials (a) and (b)charged into the storage silo was quantitatively delivered from the siloand transported to a pneumatically feeding facility. Then, the granularsynthetic resin materials were pneumatically fed from the pneumaticallyfeeding facility to the tuyere of a blast furnace in the followingconditions and blown into the furnace.

Pneumatically feeding gas: air

Flow amount of pneumatically feeding gas blown: 1300 Nm³/hr

Blown amount of granular synthetic resin material: 7.5 t/hr

Solid-gas ratio: 4.5 kg/kg

(iii) Operating Conditions of Blast Furnace

Iron running amount: 9000 t/day

Coke ratio: 447 kg/t·pig

Tuyere: blown amount of granular synthetic resin

materials: 20 kg/t·pig

blown amount of powdered coal: 100 kg/t·pig

blast amount: 7260 Nm³/minute

oxygen addition rate: 4%

blast temperature: 1000° C.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, the blastfurnace operation itself did not have any problems, and feeding problemssuch as clogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

Example 2

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into a processing and blowingtest facility for synthetic resins shown in the flow chart of FIG. 1 inthe proportions of 14.6 kg/hr and 29.2 kg/hr respectively to processthem into the granular synthetic resin materials (a) and (b). Afterblending them in the storage silo, they were pneumatically fed into ascrap-melting test furnace (vertical furnace) via the pneumaticallyfeeding pipe line and blown into the furnace from the tuyere togetherwith powdered coal. Used in this example was the scrap-melting testfurnace (content volume: 2.5 m³, pig iron production: 10 t/day) havingcombustion burners having a structure shown in FIG. 8 at plural tuyeresof the furnace casing shown in FIG. 7. In the furnace shown in FIG. 7and FIG. 8, 25 is a top; 26 is a material-charging equipment; 27 is ashut-off equipment for the top; 28 is an exhaust gas duct; 29 is atuyere part; and 30 is a combustion burner disposed at the tuyere part.Powdered coal PC and the granular synthetic resin materials SR wereblown into the furnace from a solid fuel-blowing part a in the center ofa burner diameter direction or the circumference thereof at the tuyerepart 30, and oxygen of room temperatures was blown into the furnace froman oxygen-blowing part b in the circumference thereof. Steam was blowntogether as a coolant for controlling combustion temperatures.

The processing and feeding conditions of the synthetic resins and theoperating conditions of the scrap-melting test furnace are shown below.

(i) Processing Conditions of the Synthetic Resins

Same as in Example 1.

(ii) Conditions for Pneumatically Feeding the Granular Synthetic ResinMaterials

The mixture of the granular synthetic resin materials (a) and (b)charged into the storage silo was quantitatively delivered from the siloand transported to the pneumatically feeding facility. Then, thegranular synthetic resin materials were pneumatically fed from thepneumatically feeding facility to the tuyere of the blast furnace in thefollowing conditions and blown into the furnace.

Pneumatically feeding gas: air

Flow amount of pneumatically feeding gas blown: 7.6 Nm³/hr

Blown amount of granular synthetic resin material: 43.8 kg/hr

Solid-gas ratio: 4.5 kg/kg

(iii) Operating Conditions of Scrap-melting Test Furnace

Iron running amount: 10 t/day

Coke ratio: 265 kg/t·pig

Converter slag ratio: 121 kg/t·pig

Silica rock ratio: 5 kg/t·pig -p1 Tuyere: blown amount of granularsynthetic resin

materials: 105 kg/t·pig

blown amount of powdered coal: 175 kg/t·pig

blast oxygen amount: 206 Nm³/t·pig

steam amount: 7 Nm³/t·pig

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, the operationitself of the scrap-melting test furnace did not have any problems, andfeeding problems such as clogging at the delivering part of the storagesilo and in the pneumatically feeding pipe line were scarcely caused.

Example 3

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed respectively into theprocessing and blowing facility for synthetic resins shown in the flowchart of FIG. 1 in the conditions of Operational examples 1 to 10 shownin Table 1, Table 3 and Table 5 to process them into the granularsynthetic resin materials (a) and (b), respectively. As shown in Table1, Table 3 and Table 5, contained in the processed synthetic resinmaterials were polyethylene terephthalate (PET), ABS resins and vinylchloride resins (PVC) in addition to thermoplastic resins such aspolyethylene and polypropylene. Further contained therein as otherresins were urethane resins, thermosetting resins such as phenol resins,resins containing plasticizers such as diethyl phthalate, flameretardants such as trimethyl phosphate and 2,3-dibromopropyl, glassfibers, calcium carbonate, alumina and clay, and other variousadditives. Further, earth and sand adhered to the synthetic resins werecontained therein as inorganic matters. The processing conditions of thesynthetic resins are the same as in Example 1.

After the granular synthetic resin materials (a) and (b) obtained afterprocessing were mixed in the storage silo, they were pneumatically fedto the tuyere part of the blast furnace through the pneumaticallyfeeding pipe line and blown into the furnace through a wasteplastic-blowing lance (25 mmφ). The pneumatically feeding conditions ofthe granular synthetic resin materials are shown below. The propertiesof the synthetic resins processed and fed into the furnace in respectiveOperational examples 1 to 10 are shown in Table 1, Table 3 and Table 5.

Pneumatically feeding gas: air

Flow amount of pneumatically feeding gas blown: 650 to 2600 Nm³/hr

Blown amount of granular synthetic resin materials: 3.75 to 15.0 t/hr

Solid-gas ratio: 4.5 kg/kg

Operational Examples 1 to 4

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing facility for synthetic resins in the proportions of 2.5 t/hr and5.0 t/hr respectively in the conditions shown in Table 1 to process theminto the granular synthetic resin materials (a) and (b). After blendingthem in a reservoir silo, they were pneumatically fed into the blastfurnace and blown into the furnace (pneumatically feeding gas-blownamount: 1300 Nm³/hr). The operating conditions of the blast furnace areshown in Table 2.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

Operational Example 5

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing facility for synthetic resins in the proportions of 1.5 t/hr and6.0 t/hr respectively in the conditions shown in Table 3 to process theminto the granular synthetic resin materials (a) and (b). After blendingthem in the storage silo, they were pneumatically fed into the blastfurnace and blown into the furnace (pneumatically feeding gas-blownamount: 1300 Nm³/hr). The operating conditions of the blast furnace areshown in Table 4.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

Operational Example 6

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing facility for synthetic resins in the proportions of 3.0 t/hr and4.5 t/hr respectively in the conditions shown in Table 3 to process theminto the granular synthetic resin materials (a) and (b). After blendingthem in the storage silo, they were pneumatically fed into the blastfurnace and blown into the furnace (pneumatically feeding gas-blownamount: 1300 Nm³/hr). The operating conditions of the blast furnace areshown in Table 4.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have troubles at all, and feeding any problemssuch as clogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

Operational Example 7

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing facility for synthetic resins in the proportions of 5.0 t/hr and2.5 t/hr respectively in the conditions shown in Table 3 to process theminto the granular synthetic resin materials (a) and (b). After blendingthem in the storage silo, they were pneumatically fed into a blastfurnace and blown into the furnace (pneumatically feeding gas-blownamount: 1300 Nm³/hr). The operating conditions of the blast furnace areshown in Table 4.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have troubles at all, and feeding troubles suchas clogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

Operational Example 8

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing facility for synthetic resins in the proportions of 1.50 t/hrand 2.25 t/hr respectively in the conditions shown in Table 5 to processthem into the granular synthetic resin materials (a) and (b). Afterblending them in the storage silo, they were pneumatically fed into theblast furnace and blown into the furnace (pneumatically feedinggas-blown amount: 650 Nm³/hr). The operating conditions of the blastfurnace are shown in Table 6.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

Operational Example 9

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing facility for synthetic resins in the proportions of 4.50 t/hrand 6.75 t/hr respectively in the conditions shown in Table 5 to processthem into the granular synthetic resin materials (a) and (b). Afterblending them in the storage silo, they were pneumatically fed into theblast furnace and blown into the furnace (pneumatically feedinggas-blown amount: 1930 Nm³/hr). The operating conditions of the blastfurnace are shown in Table 6.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

Operational Example 10

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing facility for synthetic resins in the proportions of 5.5 t/hr and9.5 t/hr respectively in the conditions shown in Table 5 to process theminto the granular synthetic resin materials (a) and (b). After blendingthem in the storage silo, they were pneumatically fed into a blastfurnace and blown into the furnace (pneumatically feeding gas-blownamount: 2600 Nm³/hr). The operating conditions of the blast furnace areshown in Table 6.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

TABLE 1 OPERATIONAL OPERATIONAL OPERATIONAL OPERATIONAL EXAMPLE 1EXAMPLE 2 EXAMPLE 3 EXAMPLE 4 FILM- FILM- FILM- FILM- SHAPED LUMPYSHAPED LUMPY SHAPED LUMPY SHAPED LUMPY *1 *2 *1 *2 *1 *2 *1 *2Properties (%) Polyethylene 71.00  92.00  76.00  53.50  65.00  29.00 51.00  33.00  Polypropylene 24.00  4.50 11.00  26.00  28.00  28.00 32.00  23.00  Polystyrene 5.00 0.50 7.00 13.00  3.00 31.50  11.00 23.00  PET 0.00 0.00 2.00 2.00 3.00 1.50 0.00 1.50 ABS 0.00 0.00 1.001.00 0.00 0.00 0.00 1.50 PVC 0.00 0.00 3.00 0.00 0.00 1.50 1.00 2.50Other resins 0.00 0.00 0.00 0.00 1.00 4.00 2.00 9.50 Inorganic 0.00 3.000.00 4.50 0.00 4.50 3.00 6.00 Heat value of synthetic 10697 10215 99249565 resin material charged into furnace (kcal/kg) *1: Synthetic resinsmainly comprising film-shaped synthetic resins supplied (A) *2:Synthetic resins mainly comprising lumpy synthetic resins supplied (B)

TABLE 2 Operational Operational Operational Operational ex. 1 ex. 2 ex.3 ex. 4 Iron production (t/day) 9000 9000 9000 9000 Blast temp. (° C.)1000 1000 1000 1000 Blast volume (Nm³/t.pig) 1075 1075 1075 1074 Cokerate (kg/t.pig)  395  396  396  399 Grained coal ratio (kg/t.pig)  100 100  100  100 Synthetic resin ratio (kg/t.pig)  20  20  20  20

TABLE 3 OPERATIONAL OPERATIONAL OPERATIONAL EXAMPLE 5 EXAMPLE 6 EXAMPLE7 FILM- FILM- FILM- SHAPED LUMPY SHAPED LUMPY SHAPED LUMPY *1 *2 *1 *2*1 *2 Properties (%) Polyethylene 71.00  71.00  66.50  45.67  47.00 48.50  Polypropylene 24.00  14.00  13.00  29.67  28.00  23.50 Polystyrene 5.00 5.00 8.00 13.00  18.00  16.50  PET 0.00 0.00 1.00 3.673.00 1.50 ABS 0.00 0.00 1.00 1.00 0.00 0.00 PVC 0.00 2.50 2.50 0.00 1.002.50 Other resins 0.00 2.50 5.00 3.33 3.00 3.00 Inorganic 0.00 5.00 2.003.67 0.00 4.50 Heat value of synthetic 10194 9990 9941 resin materialcharged into furnace (kcal/kg) *1: Synthetic resins mainly comprisingfilm-shaped synthetic resins supplied (A) *2: Synthetic resins mainlycomprising lumpy synthetic resins supplied (B)

TABLE 4 Operational Operational Operational ex. 5 ex. 6 ex. 7 Ironproduction (t/day) 9000  9000  9000  Blast temp. (° C.) 950 950 925Blast volume (Nm³/t.pig) 1104  1104  1120  Coke rate (kg/t.pig) 403 405409 Grained coal ratio (kg/t.pig) 100 100 100 Synthetic resin ratio(kg/t.pig)  20  20  20

TABLE 5 OPERATIONAL OPERATIONAL OPERATIONAL EXAMPLE 8 EXAMPLE 9 EXAMPLE10 FILM- FILM- FILM- SHAPED LUMPY SHAPED LUMPY SHAPED LUMPY *1 *2 *1 *2*1 *2 Properties (%) Polyethylene 66.00  71.00  62.00  43.67  41.50 45.45  Polypropylene 24.00  14.00  13.00  26.33  26.50  19.39 Polystyrene 8.00 4.67 8.00 13.00  18.00  16.42  PET 0.00 0.00 4.20 2.203.60 4.23 ABS 0.00 0.00 1.00 1.00 0.00 3.16 PVC 1.00 1.00 2.50 3.33 2.501.71 Other resins 1.00 2.67 7.30 5.13 6.40 1.03 Inorganic 0.00 6.67 2.005.33 1.50 8.61 Heat value of synthetic resin 10238 9674 9480 materialcharged into furnace (kcal/kg) *1: Synthetic resins mainly comprisingfilm-shaped synthetic resins supplied (A) *2: Synthetic resins mainlycomprising lumpy synthetic resins supplied (B)

TABLE 6 Operational Operational Operational ex. 8 ex. 9 ex. 10 Ironproduction (t/day) 9000 9000 9000 Blast temp. (° C.) 1000 1000 1000Blast volume (Nm³/t.pig) 1071 1077 1080 Coke rate (kg/t.pig)  408  388 378 Grained coal ratio (kg/t.pig)  100  100  100 Synthetic resin ratio(kg/t.pig)  10  30  40

Example 4

Magnetic cards (including cards using paper as a laminated material andcards having a built-in IC) were fed into the processing and blowingfacility for synthetic resins shown in the flow chart of FIG. 1 andprocessed. Then, they were pneumatically supplied to a blast furnace andblown into the furnace.

Magnetic cards are used for various purposes and classified roughly intothe following two kinds depending on the thicknesses:

(1) thickness of 0.5 mm or more: cash cards, various certification cardsand the like, and

(2) thickness of less than 0.5 mm: telephone cards, tickets, variouspre-paid cards and the like.

After investigation by advance tests, it was found that with respect tothe magnetic cards described above, since the crushing of the cardshaving a thickness of less than 0.5 mm produces scale-shaped smallflakes, and the small flakes are adhered so closely that vacancy getslost when pressurized in a tank of a pneumatically feeding pipe line,lubrication between the crushed flakes is lost and that aeration isdeteriorated, and therefore feeding problems such as hanging are liableto be caused. Accordingly, in the present invention, the preceding cards(2) having a thickness of less than 0.5 mm were classified into thesynthetic resins (A) comprising principally film-shaped synthetic resinmaterials, and the preceding cards (1) having a thickness of 0.5 mm ormore were classified into the synthetic resins (B) comprisingprincipally massive synthetic resin materials, respectively. Then, theywere processed into the granular synthetic resin materials (a) and (b)respectively in the processing and blowing facility for synthetic resinsshown in the flow chart of FIG. 1.

After the granular synthetic resin materials (a) and (b) obtained afterprocessing were mixed in the storage silo, they were pneumatically fedto the tuyere part of the blast furnace through the pneumaticallyfeeding pipe line and blown into the furnace through the wasteplastic-blowing lance (25 mmφ).

The processing and pneumatically feeding conditions of the syntheticresins and the operating conditions of the blast furnace are shownbelow.

(i) Processing Conditions of the Synthetic Resins

Same as in Example 1.

(ii) Conditions for Pneumatically Feeding the Granular Synthetic ResinMaterials

The mixture of the granular synthetic resin materials (a) and (b)charged into the storage silo was quantitatively delivered from the siloand transported to the pneumatically feeding facility. Then, thegranular synthetic resin materials were pneumatically fed from thepneumatically feeding facility to the tuyere of the blast furnace in thefollowing conditions and blown into the furnace.

Pneumatically feeding gas: air

Flow amount of pneumatically feeding gas blown: 1200 Nm³/hr

Blown amount of granular synthetic resin material: 62.5 kg/min

Solid-gas ratio: 2.4 kg/kg

(iii) Operating Conditions of Blast Furnace

Iron running amount: 9000 t/day

Blast amount: 7260 Nm³/minute

Oxygen addition rate: 4%

Blast temperature: 1200° C.

Coke ratio: 447 kg/t·pig

Blown amount of powdered coal: 100 kg/t·pig

Blown amount of granular synthetic resin materials: 10 kg/t·pig

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 2 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

Example 5

Only polyethylene terephthalate resin (PET) bottle containers wereselected from plastic bottle containers recovered as wastes. They wereprocessed and pneumatically fed to the blast furnace to be blown intothe furnace. The PET bottles were selected by means of a commercialmaterial discriminating apparatus (manufactured by Toa Denpa Ind. Co.,Ltd.) or manual operation.

In Operational example 1, PET bottles were fed only to the processingline Y of the processing and blowing facility for synthetic resins shownin the flow chart of FIG. 1, and all of them were crushed into granularsynthetic resins having a diameter of 6 mm or less as caps and labelswere adhered (metal caps were removed by means of a magnetic separatorafter crushing) Then, the granular resins were pneumatically fed to theblast furnace and blown into the furnace.

In Operational example 2, PET bottles were fed only to the processingline X of the processing and blowing facility for synthetic resins shownin the flow chart of FIG. 1 and processed into granular synthetic resinmaterials having a diameter of 6 mm or less as caps and labels wereadhered (metal caps were removed by means of a magnetic separator afterroughly crushing). Then, the granular resin materials were pneumaticallyfed to the blast furnace and blown into the furnace.

The processing and pneumatically feeding conditions of the syntheticresins in Operational example 1 and Operational example 2 describedabove and the operating conditions of the blast furnace are shown below.

(i) Processing Conditions of the Synthetic Resins

Operational example 1: same as (i-2) in Example 1

Operational example 2: same as (i-1) in Example 1

(ii) Conditions for Pneumatically Feeding the Granular Synthetic ResinMaterials

In each of Operational example 1 and Operational example 2, the granularsynthetic resin materials charged into the storage silo werequantitatively delivered from the silo and transported to thepneumatically feeding facility. Then, the granular synthetic resinmaterials were pneumatically fed from the pneumatically feeding facilityto the tuyere of a blast furnace in the following conditions and blowninto the furnace.

Pneumatically feeding gas: air

Blown amount of pneumatically feeding gas: 1200 Nm³/hr

Blown amount of granular synthetic resin materials: 62.5 kg/hr

Solid-gas ratio: 2.4 kg/kg

(iii) Operating Conditions of Blast Furnace

Iron running amount: 9000 t/day

Blast amount: 7260 Nm³/minute

Oxygen addition rate: 4%

Blast temperature: 1200° C.

Coke ratio: 447 kg/t·pig

Blown amount of powdered coal: 100 kg/t·pig

Blown amount of granular synthetic resin materials: 10 kg/t·pig

The operation described above was continued for 2 days. As a resultthereof, the amount of the granular synthetic resin materials blown intothe blast furnace was not stabilized (the blown amount was pulsed) inOperational example 1, and the stopping time of blowing the granularsynthetic resin materials into the blast furnace reached up to 4.6hr/day. As a result of investigations, it became clear that the inferiordelivery of the granular synthetic resin materials from the tank in thepneumatically feeding pipe line caused this instabilization of the blownamount, to be specific, since the crushed pieces (scale-shaped smallflakes) themselves of the granular synthetic resin materials wereadhered closely to cause vacancy to get lost when applying pressure inthe tank of the pneumatically feeding pipe line, lubrication between thecrushed pieces got lost, and aeration was deteriorated as well and thatthis brought about feeding problems such as hanging.

On the other hand, feeding problems of the granular synthetic resinmaterials were not caused at all in Operational example 2 as was thecase with Operational example 1, and the operation itself of the blastfurnace did not have any problems.

According to the fuel blowing method of the present invention describedabove, synthetic resins such as plastics can be fed as fuel blown intofurnaces such as a blast furnace and a scrap-melting furnace regardlessof the forms thereof, and therefore synthetic resins which are wastescan be disposed in large quantities and utilized effectively. The fuelcost of furnaces such as a blast furnace can be reduced as well to alarge extent. Further, the fluidity, the carrying property and thecombustibility of the synthetic resins fed into furnaces can effectivelybe enhanced, and the synthetic resin materials can suitably be fed intofurnaces as fuels without bringing about any problems on the operationof the furnaces in a blast furnace and a scrap-melting furnace.

Embodiment 2

Based on the preceding knowledge that the presence of film-shapedsynthetic resin materials mixed in waste synthetic resins makes itsubstantially impossible to make use of synthetic resins as furnacefuel, the fuel blowing method of the present invention is characterizedfundamentally by accepting synthetic resins to be used for fuel into therespective processing lines in the state that the synthetic resins areclassified into synthetic resins comprising principally film-shapedsynthetic resins and other synthetic resins, processing them intogranular matters suited to pneumatically feeding solid fuel by eachdifferent step and pneumatically feeding these processed granularsynthetic resins into a furnace.

In particular, with respect to film-shaped synthetic resins, there havebeen obtained the knowledges that when they are processed by a specificmethod, granular synthetic resin materials which are very excellent influidity, carrying property and combustibility are obtained and thatblending such granular synthetic resin materials with pulverized matterssuch as massive synthetic resin materials can enhance notably thefluidity, the carrying property and the combustibility of the wholesynthetic resin materials, and a fuel blowing method constituted on thebasis of these knowledges is another characteristic of the presentinvention.

Further, particularly from the viewpoint of securing thedischargeability of granular synthetic resin materials from a storagesilo and the carrying property thereof in a pneumatically feeding pipeat high levels, it has been found that it is essential to cause therepose angle of the granular synthetic resin materials to fall in arange of a specific value, and a fuel blowing method constituted on thebasis of such knowledge is still another characteristic of the presentinvention.

FIG. 9 is a flow chart showing one example of the fuel blowing method ofthe present invention, and the present invention shall be explainedbelow based on this flow chart.

In the present invention, synthetic resins to be used for fuel areaccepted into the respective processing lines in the state that thesynthetic resins are classified into synthetic resins (A) comprisingprincipally film-shaped synthetic resins and other synthetic resins (B)(that is, comprising principally massive synthetic resin materials). Inthis connection, synthetic resin materials of other forms which areinferior in fluidity and carrying property, for example, foamedplastics, as well as the film-shaped synthetic resin materials can becontained in the synthetic resins (A).

The film-shaped synthetic resin materials shall not specifically berestricted, but according to what have been confirmed by the presentinventors through experiments, synthetic resin films having a thicknessof 100 μm or less are particularly inferior in fluidity and carryingproperty, and therefore the synthetic resin films having a thickness of100 μm or less are classified preferably into the synthetic resins (A)in a classifiable limit. It is a matter of course, however, that theyshall not necessarily be restricted to such classification standard.Further, such relatively thick synthetic resins as used for so-calledPET bottles as well as very thin films such as polyethylene films can becontained in the synthetic resins (A). Whether or not they areclassified into the synthetic resins (A) is determined according tofactors such as the compositions, the materials (for example, materialsother than synthetic resins are contained or not contained as compositematerials) and the forms of the synthetic resins as well as thethicknesses thereof.

On the other hand, the synthetic resins (B) comprise principally massivesynthetic resin materials such as plates, but it is a matter of coursethat they shall not be restricted thereto.

In short, considering the fluidity and the carrying property ofsynthetic resins collected, synthetic resins which are extremelyinferior in fluidity and carrying property in the state that they arecrushed, such as at least polyethylene films can be classified into thesynthetic resins (A), and synthetic resins such as massive plasticshaving better fluidity and carrying property than those of the aboveresins can be classified into the synthetic resins (B). The other resinscan be classified into either of the synthetic resins (A) and (B)considering the fluidity and the carrying property.

When seen from the viewpoint of the whole conversion-to-fuel system,there do not necessarily have to be strictly classified, all of thefilm-shaped synthetic resin materials out of the synthetic resins to besupplied as fuel into the synthetic resins (A), and all of the massivesynthetic resins into the synthetic resins (B), respectively.Considering the quality thereof as waste, such strict classification ispractically difficult. Accordingly, it is allowable that there arecontained to some extent, massive synthetic resin materials in thesynthetic resins (A), and film-shaped synthetic resin materials in thesynthetic resins (B).

In FIG. 9, X represents a processing line for the synthetic resins (A)comprising principally the film synthetic resin materials, and Yrepresents a processing line for the synthetic resins (B) comprisingprincipally the massive synthetic resin materials. In the processingline X, the synthetic resins (A) are molten or semi-molten by heat andthen solidified, whereby they are processed into a volume-reduced andsolidified (volume-reduced=reduced in volume) granular synthetic resinmaterial (a). Meanwhile, in the processing line Y, the synthetic resins(B) are pulverized and processed into a granular synthetic resinmaterial (b).

In the processing line X, the synthetic resins (A) are crushed (orroughly crushed), if necessary, by means of a crushing equipment 101 andthen charged into a separating equipment 102 by means of a conveyorcarrier to separate and remove only chlorine-containing macromolecularresin materials such as polyvinyl chloride and polyvinylidene chloridefrom the synthetic resins (A). Since the chlorine-containingmacromolecular resin materials such as polyvinyl chloride have a largespecific gravity as compared with those of other synthetic resins (thespecific gravity of polyvinyl chloride is 1.16 to 1.55 while that ofpolyethylene is 0.91 to 0.96, and that of polypropylene is 0.89 to0.91), the chlorine-containing macromolecular resin materials areusually separated from the synthetic resins (A) by a gravity separationsystem making use of liquid such as water or a centrifugal separationsystem in the separating equipment 102. Iron scraps mixed in thesynthetic resins are removed by means of a magnetic separator 105 (anequipment in which iron scraps are adsorbed on a magnet to remove them)in the middle of the conveyor carrier described above. When thesynthetic resins (A) are crushed by means of a granulation andsolidification equipment 103 described later, crushing by means of thecrushing equipment 101 described above is not necessarily required.Accordingly, in such case, the crushing equipment 101 may not beinstalled.

The preceding separating equipment 102 in the processing line X can bearranged in an optional position in an upstream than the granulation andsolidification equipment 103.

FIG. 10 shows one constitutional example of the separating equipment 102based on the gravity separation system. The synthetic resins (A) arecharged into a separating bath 114 containing water and separated intochlorine-containing macromolecular resin materials such as polyvinylchloride settling down in the bath and other synthetic resin materialsfloating in the bath. The settled down and separated chlorine-containingmacromolecular resin materials are discharged out of the bath by asuitable discharging means and separated from water via a screen 115 a.Then, they are discharged out of the system. On the other hand, thesynthetic resin materials other than the chlorine-containingmacromolecular resin materials, which have floated in the bath aredischarged out of the bath by a suitable discharging means and separatedfrom water via a screen 115 b. Then, they are dried in a drier 116 andsent to the following step. In FIG. 10, 117 is a drainage tank fordischarging water separated by the screens 15 a, 115 b.

FIG. 11 shows one constitutional example of the separating equipment 102based on the centrifugal separation system. This equipment comprises atubulous or spindle body 131 which is hollow in an inside thereof, aninner cylindrical body 132 equipped with a screw rotatably disposed in alongitudinal direction in the inside of this body 131, and a motor 133for rotary drive of this inner cylindrical body. In this equipment, themixture of the synthetic resin materials and a medium such as water isfed into the inside thereof from one end of the inner cylindrical body132 rotating at a high rate. The mixture is discharged into the innerspace of the body 131 from an opening provided almost in the center inthe longitudinal direction of the inner cylindrical body 132 by theaction of a centrifugal force and separated into heavy components(chlorine-containing macromolecular resins) having a larger specificgravity than that of the medium and light components (synthetic resinsother than the chlorine-containing macromolecular resins) having asmaller specific gravity with the specific gravity of the medium beingthe boundary. That is, only the heavy components out of the syntheticresin materials are collected on the inner wall surface side of the body131, and as a result thereof, the light components are separated fromthe heavy components in the radial direction of the body 131.

Provided in the inner cylindrical body 132 are a screw 135 a forcarrying the light components at a half part thereof in the longitudinaldirection and a screw 135 b for carrying the heavy componentss at theother half part thereof in the longitudinal direction with the opening134 described above being the approximate boundary. These screws 135 a,135 b have helical directions which are reverse to each other, and thescrews 135 a, 135 b carry the synthetic resin materials to the enddirections of the body on the respective sides by rotating the innercylindrical body 132. That is, the synthetic resin materials of thelight components are carried to one end of the body 131 by means of thescrew 135 a having relatively short blades and discharged from adischarging port 136 a. Meanwhile, the synthetic resin materials of theheavy components collected at the inner wall face side of the body 131are carried to the other end of the body 131 by means of the screw 135 bhaving blades extended up to the vicinity of the inner wall face of thebody 131 and discharged from a discharging port 136 b. On the hand, themedium such as water is discharged out of the equipment from adischarging port 137 provided approximately at the central part of thebody 131.

According to such equipment, the synthetic resin materials separatedinto the light components and the heavy components respectively can bedischarged out of the equipment in the condition that the water contentis very small.

As described above, the synthetic resins (A) from which thechlorine-containing macromolecular resin materials have been separatedby means of the separating equipment 102 are charged into thegranulation and solidification equipment 103 and processed into thegranular synthetic resin material (a) which is volume-reduced andsolidified.

In the granulation and solidification equipment 103, the volume-reducedsolidification—granulation of the synthetic resins (A) is carried out byany of the following methods [1] to [3] to obtain the granular syntheticresin material (a): [1] a method in which after melting the syntheticresins (A) by heating, they are cooled down and solidified, and thissolidified synthetic resin material is cut and pulverized, [2] a methodin which the synthetic resins (A) are cut or crushed (this cutting orcrushing may be carried out by means of the crushing equipment 101described above instead of the granulation and solidification equipment103); this cut or crushed synthetic resin material is semi-molten byheating or frictional heat generated by the cutting or crushingdescribed above; a semi-molten synthetic resin material is contractedand solidified by rapidly cooling, wherein the synthetic resin materialis contracted and solidified into a granular form or the contracted andsolidified synthetic resin material is pulverized, to thereby obtain thegranular synthetic resin material (a), and [3] a method as oneembodiment of the method [2] described above, in which the syntheticresins (A) are cut or crushed by means of rotary blades which arerotated at a high speed, and the synthetic resins are semi-molten byfrictional heat generated by the above cutting or crushing; then, thissemi-molten synthetic resin material is contracted and solidified byrapidly cooling by spraying water, wherein the synthetic resin materialis contracted and solidified into a granular form, or contracted andsolidified and immediately crushed by means of the rotary bladesdescribed above to thereby obtain the granular synthetic resin material(a).

Among these methods, a typical example of the method [1] is a method inwhich after completely molting the synthetic resins (A) and molding thisinto strings by extruding with an extruding machine, they are cut into agranular form, whereby the granular synthetic resin material (a) isobtained. In addition to the above methods, various processing methodscan be employed.

In contrast with this, the methods [2] and [3] are methods in which thesynthetic resins (A) are contracted and solidified by semi-melting themwithout completely melting and then rapidly cooling by spraying water,wherein the synthetic resins (A) are contracted and solidified into agranular form, or the contracted and solidified synthetic resins (A) arepulverized into a granular form, whereby the granular synthetic resinmaterial (a) is obtained. The present inventors have found that thegranular synthetic resin material (a) obtained by the methods [2] and[3] (particularly the method [3]) shows very excellent fluidity andcarrying property as compared with not only those of the pulverizedmatters of the film-shaped synthetic resin materials but also those ofthe pulverized matters of the massive synthetic resin materials and isvery excellent as well in combustibility and that the carrying propertyand the combustibility of the whole synthetic resins can notably beraised by using them in a mixture with the pulverized matters of themassive synthetic resin materials. Accordingly, in the fuel blowingmethod of the present invention, granular contraction and solidificationor contraction and solidification—granulation of the synthetic resins(A) is most preferably carried out by the method [2] or [3] in thegranulation and solidification equipment 2 to obtain the granularsynthetic resin material (a).

The granular synthetic resin material (a) thus obtained is sieved bymeans of a sieving equipment 104, and only grains having a prescribedgrain diameter (for example, −6 mm) or less are sent to a storage silo111 via a path 125. In this constitutional example, the path 125 isconstituted by a pneumatically feeding pipe (in the drawing, 112 is anair blower), and the granular synthetic resin material (a) ispneumatically fed (pneumatic transportation, hereinafter the same shallapply) to the storage silo 111. On the other hand, the granularsynthetic resin material having a grain diameter exceeding theprescribed grain diameter is returned to a carrying line present at theinlet side of a granulation and solidification equipment 103 via a path126 (in the drawing, 112 is an air blower) which is a pneumaticallyfeeding pipe and recharged into the granulation and solidificationequipment 103 together with the synthetic resins (A). A position towhich this coarsely granulated synthetic resin material is sent back isoptional, and it can be sent back to respective positions (usually, atransporting line) such as, for example, between the separatingequipment 102 and the granulation and solidification equipment 103,between the magnetic separator 105 and the separating equipment 102, andthe inlet side of the crushing equipment 101. In some case, it can besupplied as well to the processing line Y. When it is supplied to thisprocessing line Y, it can be supplied to respective positions (usually,a transporting line) such as, for example, the inlet side of a primarycrushing equipment 106, between the primary crushing equipment 106 and asecondary crushing equipment 107, between the secondary crushingequipment 107 and a classifier 108 and between the classifier 108 and amilling equipment 110. In addition to the above, the coarsely granulatedsynthetic resin material may be taken out of the system and chargeddirectly into other steps (for example, charged into the tops of a blastfurnace and a scrap melting furnace or charged directly into a coke ovenand a sintering furnace).

On the other hand, in the processing line Y, the synthetic resins (B)are coarsely crushed (for example, crushed to a grain diameter of about50 mm) by means of the primary crushing equipment 106 and then chargedinto the secondary crushing equipment 107 by conveyor carrying to besecondarily crushed (for example, crushed to a grain diameter of about20 mm) The primarily crushed synthetic resins (B) are subjected toremoval of iron scraps mixed therein by means of the magnetic separator105 (an equipment for adsorbing iron scraps on a magnet to remove them)in the middle of the conveyor carrying described above.

The secondarily crushed synthetic resins (B) are charged into theclassifier 108 by conveyor carrying, wherein foreign matters such asmetals, earth and sand, and stones are separated by a method such aswind classification. Then, they are sent to the separating equipment 109via a path 127 a, and only the chlorine-containing macromolecular resinmaterials are separated and removed from the synthetic resins (B). ThePVC separating method and the constitutional example of this separatingequipment 109 are the same as those of the separating equipment 102described previously, and therefore the explanation thereof shall beomitted. The arrangement of the separating equipment 109 in theprocessing line Y shall not be restricted to the examples of theinvention, and it can be arranged in optional positions at an upstreamside or a downstream side than a milling equipment 110, for example,between the primary crushing equipment 106 and the secondary crushingequipment 107, between the secondary crushing equipment 107 and theclassifier 108, and the exit side of the milling equipment 110.

The synthetic resins (B) from which the chlorine-containingmacromolecular resin materials have been separated and removed are sentto the crushing equipment 110 (tertiary crushing equipment) and crushedto a prescribed diameter (for example, −6 mm) or less, whereby thegranular synthetic resin material (b) is obtained. This granularsynthetic resin material (b) is sent to the storage silo 111 via a path127 c. In this constitutional example, the paths 127 a to 127 c areconstituted by pneumatic feeding pipes (in the drawing, 112 is an airblower), and the granular synthetic resin material (b) is pneumaticallyfed into the storage silo 111.

The mixture of the granular synthetic resin materials (a) and (b) storedin the storage silo 111 is carried by a conveyor or pneumatically fedinto a blowing means 113 and pneumatically fed into a furnace such as ablast furnace via this blowing means 113. Then, the mixture is blowninto the furnace from the tuyere thereof through this blowing means 113.

In the constitutional example shown in FIG. 9, the magnetic separator105 is provided each at one portion in the processing lines X and Y,respectively, but the magnetic separators 105 may be disposed at pluralportions in the respective processing lines X and Y.

The crushing systems of various crushing equipments (including as wellthe milling equipment 110) disposed in the processing lines X and Y areoptional. In addition to a crushing system carried out only byconventional mechanical means, there can be applied as well, forexample, a so-called freeze-crushing system in which matters to beprocessed are crushed in a frozen state.

Usually, auxiliary facilities such as a yard drying facility forsynthetic resins carried in are provided at the inlet side of theprocessing facility shown in FIG. 9.

As described previously, the amounts of the synthetic resins (A)comprising principally the film-shaped synthetic resin materials and theother synthetic resins (B) which are fed to the respective processinglines are dispersed to some extent according to the lapse of time incertain cases due to the properties of wastes. In the case of limitingthe time to a relatively short period (for example, several hours tosome ten hours), only either one kind of the synthetic resins issupplied, and therefore it is possible that the synthetic resinsprocessed and pneumatically fed into a furnace is tentatively limitedonly to either one of the synthetic resins (A)—the granular syntheticresin material (a) and the synthetic resins (B)—the granular syntheticresin material (b). Also, it is possible that only either one of thegranular synthetic resin material (a) and the granular synthetic resinmaterial (b) is pneumatically fed tentatively into the furnace becauseof reasons other than the above one. Further, the granular syntheticresin materials (a) and (b) can be stored in different silos to bepneumatically fed into the furnace via separate paths.

As described previously, the granular synthetic resin material (a)obtained by carrying out granular contraction and solidification orcontraction and solidification-granulation has a relatively porousproperty and a large specific surface area. In addition thereto, sincethe granular synthetic resin material (a) has a roundish form on thewhole, it shows excellent combustibility and fluidity, and thecombustibility, the fluidity and the carrying property of the wholegranular synthetic resin materials supplied to a furnace can effectivelybe raised by mixing the granular synthetic resin material (a) with thegranular synthetic resin material (b). That is, with respect to thecombustibility, when the mixture of the granular synthetic resinmaterial (a) and the granular synthetic resin material (b) is blown intothe furnace, the granular synthetic resin material (a) having a goodcombustibility burns rapidly to ignite quickly the granular syntheticresin material (b), and this increases markedly the combustibility ofthe whole granular synthetic resin materials blown into the furnace.

Further, also with respect to the fluidity and the carrying property, alubricant function which enhances the fluidity of the whole granularsynthetic resin materials is displayed by causing the granular syntheticresin material (a) which has a roundish form and is excellent influidity and carrying property to be contained in the granular syntheticresin materials. As a result thereof, the fluidity and the carryingproperty of the whole granular resin materials are improved to a largeextent.

EXAMPLES Example 1

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into a test processing andblowing facility for synthetic resins shown in the flow chart of FIG. 9in the proportions of 2.8 kg/hr and 5.6 kg/hr respectively to processthem into the granular synthetic resin materials (a) and (b). Afterblending them in a storage silo, they were pneumatically fed into a testblast furnace through a pneumatically feeding pipe line and blown intothe furnace from the tuyere together with powdered coal. The processingand feeding conditions of the synthetic resins and the operatingconditions of the test blast furnace are shown below.

(i) Processing Conditions of the Synthetic Resins

(i-1) Synthetic Resins (A)

After roughly crushing the synthetic resins and separating polyvinylchloride materials therefrom according to the flow chart of FIG. 9, theywere subjected to contraction and solidification—granulation processingby the method [3] described previously to process them into the granularsynthetic resin material (a) having a grain diameter of 6 mm or less.Then, this was transferred into a storage silo.

(i-2) Synthetic Resins (B)

The synthetic resins were subjected to primary crushing, secondarycrushing, separation and removal of polyvinyl chloride materials andmilling processing according to the flow chart of FIG. 9 to process theminto the granular synthetic resin material (b) having a grain diameterof 6 mm or less, and then this was transferred into the storage silo.

(ii) Conditions for Pneumatically Feeding the Granular Synthetic ResinMaterials

The mixture of the granular synthetic resin materials (a) and (b)charged into the storage silo was quantitatively delivered from the siloand transported to a pneumatically feeding facility. Then, the granularsynthetic resin materials were pneumatically fed from the pneumaticallyfeeding facility to the tuyere of a blast furnace in the followingconditions and blown into the furnace.

Pneumatically feeding gas: air

Flow amount of pneumatically feeding gas blown: 2.6 Nm³/hr

Blown amount of granular synthetic resin materials: 8.4 kg/hr

Solid-gas ratio: 2.5 kg/kg

(iii) Operating Conditions of Blast Furnace

Iron running amount: 10 t/day

Coke ratio: 485 kg/t·pig

Tuyere: blown amount of granular synthetic resin materials: 20 kg/t·pig

blown amount of powdered coal: 100 kg/t·pig

blast amount: 610 Nm³/minute

oxygen addition rate: 4%

blast temperature: 1000° C.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

In this operational example, a polyvinyl chloride material accounted forabout 3% of the synthetic resins fed into the processing lines X and Y,and about 99% of this polyvinyl chloride material could be separated andrecovered by means of the separating equipment. Further, the furnace gaswas sampled during the whole operation to analyze the gas compositionthereof, and the result showed that HCl was scarcely detected.

Example 2

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the test processing andblowing facility for synthetic resins shown in the flow chart of FIG. 9in the proportions of 2.8 kg/hr and 5.6 kg/hr respectively to processthem into the granular synthetic resin materials (a) and (b). Afterblending them in the storage silo, they were pneumatically fed into thetest blast furnace via the pneumatically feeding pipe line and blowninto the furnace from the tuyere together with powdered coal. Theprocessing and feeding conditions of the synthetic resins and theoperating conditions of the test blast furnace are shown below.

(i) Processing Conditions of the Synthetic Resins

Same as in Example 1.

(ii) Conditions for Pneumatically Feeding the Granular Synthetic ResinMaterials

Same as in Example 1.

(iii) Operating Conditions of Blast Furnace

Iron running amount: 10 t/day

Coke ratio: 547 kg/t·pig

Tuyere: blown amount of granular synthetic resin materials: 20 kg/t·pig

blown amount of powdered coal: 100 kg/t·pig

blast amount: 1714 Nm³/minute

oxygen addition rate: 4%

blast temperature: 1000° C.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the reservoir silo and in thepneumatically feeding pipe line were scarcely caused.

In this operational example, a polyvinyl chloride material accounted forabout 3% of the synthetic resins fed into the processing lines X and Y,and about 99% of this polyvinyl chloride material could be separated andrecovered by means of the separating equipment. Further, the furnace gaswas sampled during the whole operation to analyze the gas compositionthereof, and the result showed that HCl was scarcely detected.

Example 3

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing facility for synthetic resins shown in the flow chart of FIG. 9in the proportions of 2.50 t/hr and 5.23 t/hr respectively to processthem into the granular synthetic resin materials (a) and (b). Afterblending them in a storage silo, they were pneumatically fed into ablast furnace via the pneumatically feeding pipe line and blown into thefurnace from the tuyere together with powdered coal. The processing andfeeding conditions of the synthetic resins and the operating conditionsof the blast furnace are shown below.

(i) Processing Conditions of the Synthetic Resins

Same as in Example 1.

(ii) Conditions for Pneumatically Feeding the Granular Synthetic ResinMaterials

The mixture of the granular synthetic resin materials (a) and (b)charged into the storage silo was quantitatively delivered from the siloand transported to the pneumatic feeding facility. Then, the granularsynthetic resin materials were pneumatically fed from the pneumaticallyfeeding facility to the tuyere of the blast furnace in the followingconditions and blown into the furnace.

Pneumatically feeding gas: air

Flow amount of pneumatically feeding gas blown: 1300 Nm³/hr

Solid-gas ratio: 4.5 kg/kg

(iii) Operating Conditions of Blast Furnace

Iron running amount: 9000 t/day

Coke ratio: 447 kg/t·pig

Tuyere: blown amount of granular synthetic resin materials: 20 kg/t·pig

blown amount of powdered coal: 100 kg/t·pig

blast amount: 7260 Nm³/minute

oxygen addition rate: 4%

blast temperature: 1000° C.

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, blast furnaceoperation itself did not have any problems, and feeding problems such asclogging at the delivering part of the storage silo and in thepneumatically feeding pipe line were scarcely caused.

In this operational example, the chlorine-containing resin material suchas polyvinyl chloride accounted for about 3% of the synthetic resins fedinto the processing lines X and Y, and about 99% of thischlorine-containing macromolecular resin material could be separated andrecovered by means of the separating equipment. Further, the furnace gaswas sampled during the whole operation to analyze the gas compositionthereof, and the result sshowed that HCl was scarcely detected.

Example 4

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed into the processing andblowing test facility for synthetic resins shown in the flow chart ofFIG. 9 in the proportions of 14.6 kg/hr and 29.2 kg/hr respectively toprocess them into the granular synthetic resin materials (a) and (b).After blending them in the storage silo, they were pneumatically fedinto a scrap-melting test furnace (vertical furnace) via a pneumaticallyfeeding pipe line and blown into the furnace from the tuyere togetherwith powdered coal. Used in this example was the scrap-melting testfurnace (content volume: 2.5 m³, pig iron production: 10 t/day) havingcombustion burners at plural tuyeres of the furnace casing.

The processing and feeding conditions of the synthetic resins and theoperating conditions of the scrap-melting test furnace are shown below.

(i) Processing Conditions of the Synthetic Resins

Same as in Example 1.

(ii) Conditions for Pneumatically Feeding the Granular Synthetic ResinMaterials

The mixture of the granular synthetic resin materials (a) and (b)charged into the storage silo was quantitatively delivered from the siloand transported to the pneumatically feeding facility. Then, thegranular synthetic resin materials were pneumatically fed from thepneumatically feeding facility to the tuyere of a blast furnace in thefollowing conditions and blown into the furnace.

Pneumatically feeding gas: air

Flow amount of pneumatically feeding gas blown: 7.6 Nm³/hr

Blown amount of granular synthetic resin material: 43.8 kg/hr

Solid-gas ratio: 4.5 kg/kg

(iii) Operating Conditions of Scrap-melting Test Furnace

Iron running amount: 10 t/day

Coke ratio: 265 kg/t·pig

Converter slag ratio: 121 kg/t·pig

Silica rock ratio: 5 kg/t·pig

Tuyere: blown amount of granular synthetic resin materials: 105 kg/t·pig

blown amount of powdered coal: 175 kg/t·pig

blast oxygen amount: 206 Nm³/minute

steam amount: 7 Nm³/minute

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace for 7 days. As a result thereof, the operationitself of the scrap-melting test furnace did not have any problems, andfeed problems such as clogging at the delivering part of the storagesilo and in the pneumatically feeding pipe line were scarcely caused.

In this operational example, the polyvinyl chloride material accountedfor about 3% of the synthetic resins fed into the processing lines X andY, and about 99% of this polyvinyl chloride material could be separatedand recovered by means of the separating equipment. Further, the furnacegas was sampled during the whole operation to analyze the gascomposition thereof, and the result showed that HCl was scarcelydetected.

Example 5

The synthetic resins (A) comprising principally film-shaped syntheticresin materials and the synthetic resins (B) comprising principallymassive synthetic resin materials were fed respectively into theprocessing and blowing facility for synthetic resins shown in the flowchart of FIG. 9 in the conditions of Operational examples 1 to 4 shownin Table 7 and Table 8 to process them into the granular synthetic resinmaterials (a) and (b), respectively. As shown in Table 7 and Table 8,contained in the processed synthetic resin materials were polyethyleneterephthalate (PET), ABS resins and polyvinyl chloride resins (PVC) inaddition to thermoplastic resins such as polyethylene and polypropylene.Further contained therein as other resins were urethane resins,thermosetting resins such as phenol resins, resins containingplasticizers such as diethyl phthalate, flame retardants such astrimethyl phosphate and 2,3-dibromopropyl, glass fibers, calciumcarbonate, alumina and clay, and other various additives. Further, earthand sand adhered to the synthetic resins were contained therein asinorganic matters. The processing conditions of the synthetic resins arethe same as in Example 1.

After the granular synthetic resin materials (a) and (b) obtained afterprocessing were mixed in the storage silo, they were pneumatically fedto the tuyere part of a blast furnace through a pneumatically feedingpipe line and blown into the furnace through a waste plastic-blowinglance (25 mmφ) The pneumatically feeding conditions of the granularsynthetic resin materials are shown below. The properties of thesynthetic resins processed and fed into the furnace in respectiveOperational examples 1 to 4 are shown in Table 7 and Table 8, and theoperating conditions of the blast furnace are shown in Table 9.

Pneumatically feeding gas: air

Flow amount of pneumatically feeding gas blown: 1300 Nm³/hr

Blown amount of granular synthetic resin material: 7.5 t/hr

Solid-gas ratio: 4.5 kg/kg

The granular synthetic resin materials thus obtained were continued tobe blown into the furnace. As a result thereof, blast furnace operationitself did not have any problems, and feeding problems such as cloggingat the delivering part of the storage silo and in the pneumatic feedingpipe line were scarcely caused.

Further, the furnace gas was sampled during the whole operation toanalyze the gas composition thereof, and the result showed that HCl wasscarcely detected.

TABLE 7 OPERATIONAL EXAMPLE 1 Supplied synthetic OPERATIONAL EXAMPLE 2resins Supplied synthestic resins FILM- Total after FILM-SHAPED Totalafter SHAPED *1 LUMPY *2 treatment *1 LUMPY *2 treatment Quantitysupplied (t/hr) 2.89 5.57 7.50 3.21 5.21 7.50 Properties (%)Polyethylene 71.00  66.00  75.86  51.00  46.20  53.52  Polypropylene11.00  14.00  14.45  27.50  29.50  32.12  Polystyrene 2.00 4.00 3.592.00 6.80 5.47 PET 0.00 0.00 0.00 1.50 1.00 1.34 ABS 0.00 0.00 0.00 2.000.00 0.86 PVC 11.00  11.00  1.04 8.60 11.50  0.95 Other resins 0.00 2.001.49 2.40 2.00 2.42 Inorganic 5.00 3.00 3.57 5.00 3.00 3.43 Heat valueof synthetic resin 10354 10146 material charged into furnace (kcal/kg)*1 Synthetic resins mainly comprising film-shaped synthetic resin (A) *2Synthetic resins mainly comprising lumpy synthetic resin (B)

TABLE 8 OPERATIONAL EXAMPLE 3 OPERATIONAL EXAMPLE 4 Supplied syntheticSupplied synthetic resins resins FILM- Total after FILM-SHAPED Totalafter SHAPED *1 LUMPY *2 treatment *1 LUMPY *2 treatment Quantitysupplied (t/hr) 3.15 5.21 7.49 4.20 4.70 7.50 Properties (%)Polyethylene 43.20  41.30  46.47  39.50  33.00  42.06  Polypropylene23.40  27.60  28.87  22.40  28.50  30.07  Polystyrene 9.50 11.20  11.67 9.10 11.20  11.83  PET 1.50 1.00 1.33 1.50 1.00 1.47 ABS 3.40 0.00 1.393.40 1.20 2.34 PVC 8.60 9.80 0.77 12.40  14.80  1.20 Other resins 4.806.10 5.98 6.10 7.30 7.55 Inorganic 5.60 3.00 3.52 5.60 3.00 3.47 Heatvalue of synthetic resin 9915 9795 material charged into furnace(kcal/kg) *1 Synthetic resins mainly comprising film-shaped syntheticresin (A) *2 Synthetic resins mainly comprising lumpy synthetic resin(B)

TABLE 9 Operational Operational Operational Operational ex. 1 ex. 2 ex.3 ex. 4 Iron production (t/day) 9000 9000 9000 9000 Blast temp. (° C.)1000 1000 1000 1000 Blast volume (Nm³/t.pig) 1074 1076 1077 1077 Cokerate (kg/t.pig)  395  395  396  398 Grained coal ratio (kg/t.pig)  100 100  100  100 Synthetic resin ratio (kg/t.pig)  20  20  20  20

According to the fuel blowing method of the present invention describedabove, synthetic resins such as plastics can be fed as fuel blown intofurnaces such as a blast furnace and a scrap-melting furnace regardlessof the forms thereof and without causing problems by chlorine-containingmacromolecular resins such as polyvinyl chloride and the like containedin synthetic resins, and therefore synthetic resins which are wastes canbe disposed in large quantities and utilized effectively. Fuel cost offurnaces such as a blast furnace can be reduced as well to a largeextent. Further, the fluidity, the carrying property and thecombustibility of synthetic resins fed into furnaces can effectively beenhanced, and synthetic resin materials can suitably be fed intofurnaces as fuels without bringing about any problems on the operationof furnaces in a blast furnace and a scrap-melting furnace.

Embodiment 3

The present inventors continued intensively investigations in order tosolve the problems described above.

First of all, it has been found that crushing sheet-shaped syntheticresins merely into small sheet-shaped pieces having a prescribed graindiameter as is the case with usual solid synthetic resin materialscauses lubrication between the small synthetic resin material pieces toget lost and therefore makes it impossible to deliver well the smallresin material pieces from a tank or causes clogging in a pipe lineduring pneumatic feeding because the small resin material pieces areadhered closely to each other to cause a gap between the smallsheet-shaped pieces to get lost when applying pressure in the tank, andtherefore a space for causing gas to blow through gets lost.

Accordingly, the small sheet-shaped pieces have to be prevented frombeing adhered closely to each other in the tank or during pneumaticallyfeeding. That is, the close adhesion described above can be prevented bymaking the small sheet-shaped pieces themselves roundish, that is,granulating the small pieces by semi-melting or melting them to form agap between the grains, or as another method, interposing granularsynthetic resin materials having a different shape between the smallsheet-shaped pieces to thereby form a gap between the small sheet-shapedpieces. Thus, it has been found that a gap through which air is blowncan be formed between the small sheet-shaped pieces and therefore thefluidity and the carrying property are improved.

The present embodiment relates to a process for granulating wastesynthetic resin materials as pre-processing of the waste synthetic resinmaterials in prior to blowing them into a vertical metallurgicalfurnace, characterized by comprising the steps of:

(P) classifying the waste synthetic resin materials, according to theshapes thereof, into film-shaped synthetic resin materials, solidsynthetic resin materials and sheet-shaped synthetic resin materialshaving an intermediate shape between the film-shaped synthetic resinmaterials and the solid synthetic resin materials,

(A) subjecting the film-shaped synthetic resin materials to crushingprocessing into small film pieces and subjecting the resulting smallfilm pieces to melting•solidification and granulation processing tothereby prepare a synthetic resin grain (a),

(B) subjecting the solid synthetic resin materials to crushingprocessing to thereby prepare a synthetic resin grain (b),

(C) subjecting the sheet-shaped synthetic resin material described aboveto crushing processing into small sheet pieces (C₀) having a smallermaximum size than the maximum size of the small film pieces describedabove and subjecting the resulting small sheet pieces tomelting•solidification and granulation processing to thereby prepare asynthetic resin grain (C).

Next, the embodiment of the present invention shall be explained withreference to the drawings.

FIG. 12 is a flow sheet showing one example of the embodiment of thepresent invention. Waste synthetic resin materials generated in themarket are classified into film-shaped synthetic resin materials, solidsynthetic resin materials and sheet-shaped synthetic resin materials inthe classifying step (P). The classification can be effectuated byconventional methods. In order to carry out effectively the granulationin the step (C), the thickness of the sheet-shaped synthetic resinmaterial falls preferably in a range of 100 μn to 3 mm.

After cutting the film-shaped synthetic resin materials into aprescribed shape by means of a crushing equipment 201, they aretentatively adhered into piled up small pieces of the film-shapedsynthetic resin by cutting frictional heat, and therefore they aredispersed by means of a separator 202. The small film pieces obtained byprocessing the dispersed small synthetic resin pieces by means of amagnetic separator 203 to remove iron scraps are suitably passed througha material discriminator 204 to discriminate the kinds of the syntheticresin materials.

Then, the small film pieces are charged into a melting•solidifying andgranulating equipment 205 to subject them to prescribed processing.

FIG. 13 is a drawing for explaining the function of themelting•silidifying and granulating equipment. The small film pieces arefed into a rotary crusher 233 provided in a crushing chamber 232 from acharging port 231. The small film pieces are crushed small andsemi-molten or completely molten by frictional heat. The small filmpieces discharged from a pair of the rotary crushers 233 are rapidlycooled down by a cooling medium (for example, water spray) sprayed froma nozzle 234 and contracted and solidified into a granular shape to bedischarged from a discharging port 235 in the form of synthetic resingrains (a).

FIG. 14 is a drawing for explaining a principle in which the small filmpieces are granulated by crushing small by means of the rotary crusher233 provided in the melting•silidifying and granulating equipment shownin FIG. 13, heating by frictional heat and soon rapidly cooling down.The small film pieces 241 are cut and crushed by means of a rotary blade242 rotating at a high rate and cooled down by a cooling fluid, wherebythe synthetic resin grains (a) are obtained. FIG. 14 (i) shows the casewhere the temperatures are elevated by frictional heat in crushing butthe small film pieces are scarcely molten or are semi-molten, and FIG.14 (ii) shows the case where the synthetic resin grains (a) are obtainedby melting the small film pieces by frictional heat and cooling them bythe cooling fluid.

The case where the synthetic resin grains having a prescribed graindiameter of D₀ mm or less as a target grain diameter are obtained shallbe considered. As the rotating rate of the rotary crusher 233 and theprocessing time are increased, the temperatures of the small film piecesare increased and molten, while the maximum size of the crushed smallfilm pieces are decreased as the rotating rate and the processing timeare increased. The maximum size reaches the target value D₀ mm or lessthrough such the course, wherein the crushing conditions are adjusted sothat the temperatures are controlled to a temperature T₀ which is lowerby a prescribed value than the melting point, and the crushed small filmpieces are rapidly cooled down when both the maximum size and thetemperatures of the crushed small film pieces satisfy the aboveconditions.

In the case where the temperature does not reach T₀ while the maximumsize reaches D₀ mm or less, the temperature is controlled so that it ismore quickly elevated while suppressing an increase in the crushingrate. In contrast with this, in the case where the maximum size of thesmall film pieces does not reach D₀ mm or less while the temperature ofthe small film pieces reaches T₀, the crushing rate is controlled sothat it is more quickly elevated while suppressing an increase in thetemperature. Thus, the grain diameter is controlled bymelting•solidification and granulation processing.

The melting•solidification and granulation processing is effectuated inthe manner as described above, and the synthetic resins thus obtainedare treated by means of a sieving•separating equipment 206, whereby thesynthetic resin grains (a) are obtained. They are stored in a storagetank 207 [hereinabove, step (A)].

The solid synthetic resin materials are roughly crushed by means of aprimary crusher 208 and treated in a primary magnetic separator 209 toremove iron scraps. Then, they are finely crushed by means of asecondary crusher 210 and treated in a secondary magnetic separator 211to remove iron scraps and other foreign matters. Subsequently, thesynthetic resin materials tentatively adhered to each other by crushingfrictional heat are dispersed by means of a separator 212. The dispersedsynthetic resin materials are suitably passed through a materialdiscriminating equipment 213 to analyze the materials of the syntheticresin materials. Then, the synthetic resin materials are treated in asieving and separating equipment 214 to obtain the synthetic resingrains (a). They are stored in a storage tank 216 [hereinabove, step(B)].

First, the sheet-shaped synthetic resin materials are roughly crushed bymeans of a primary crusher 217 and treated in a primary magneticseparator 218 to remove iron scraps as is the case with the processingof the solid synthetic resin materials. Then, they are finely crushed bymeans of a secondary crusher 219 and treated in a secondary magneticseparator 220 to remove iron scraps and other foreign matters.Subsequently, the synthetic resin materials tentatively adhered to eachother by crushing frictional heat are dispersed by means of a separator221, whereby the small sheet pieces (C₀) are obtained. The small sheetpieces (C₀) have to have a smaller maximum size than the maximum size ofthe small film pieces described above. This is because when the smallsheet pieces are semi-molten or molten by frictional heat generated inthe following melting•solidification and granulation processing togranulate them, too large size causes the frictional heat to betransmitted deeply into the inside of the small sheet pieces to preventthem from being semi-molten or molten and therefore makes it difficultto granulate the small sheet pieces. Then, the synthetic resin materialsare suitably passed through a material discriminating equipment 222 toanalyze the materials of the synthetic resin materials. Subsequently,the small sheet pieces are charged into a melting•solidifying andgranulating equipment 223 to subject them to prescribed processing. Inthe melting•solidification and granulation processing, the small sheetpieces are granulated by semi-melting or melting and therefore increasein thickness as well as becoming roundish. Then, the synthetic resinmaterials are treated in a sieving and separating equipment 224 toobtain the synthetic resin grains (b). They are stored in a storage tank225 [hereinabove, step (C)].

The synthetic resin grains remaining on the sieves in the sieving andseparating processing in the steps (A) to (C) can be returned to therespective crushing processings to reuse them.

FIG. 15 shows a pneumatically feeding facility 250 for blowing thesynthetic resin grains obtained by subjecting the waste synthetic resinmaterials to granulation processing as described above into a blastfurnace.

The synthetic resin grains (a), (b) and (c) are delivered from therespective storage tanks 207, 216 and 225 and suitably blended to bepneumatically fed to a service tank 251. The blended synthetic resingrains are pneumatically transported from the service tank 251 into astorage tank 252 and sent out of a blowing tank 254 via an equalizingtank 253. Then, the synthetic resin grains are blown into a blastfurnace 259 from a blowing tube 258 mounted at a tuyere 257 of the blastfurnace in a blast furnace facility 256.

FIG. 16 is a flow sheet showing one example of the embodiment of thepresent invention. A step (A) and a step (B) are the same as those inFIG. 12 but a step (D) is different from the step (C) described above.That is, in the step (D), the small sheet pieces (C₀) prepared in themiddle of the step (C) described above are blended with the syntheticresin grains (b) prepared in the step (B) without subjecting the smallsheet pieces to melting•solidification and granulation processing tothereby prepare the synthetic resin grains.

EXAMPLES

Next, the present invention shall be explained in further detail withreference to examples.

The synthetic resin grains (a), (b) and (c) prepared by subjecting wastesynthetic resin materials to granulation processing based on thepre-processing step shown in FIGS. 12 and 13 were compounded and mixedin a prescribed proportion and then blown into a blast furnace by meansof the pneumatically feeding facility shown in FIG. 15 (Example 1).Also, the synthetic resin grains (a), (b) and (c) prepared by subjectingwaste synthetic resin materials to granulation processing based on thepre-processing step shown in FIGS. 16 and 13 were compounded and mixedin a prescribed proportion and then blown into the blast furnace bymeans of the pneumatically feeding facility shown in FIG. 15 (Example2). In contrast with this, for the sake of comparison, the sheet-shapedsynthetic resins were processed in the same manner as in the step (B),and the resulting synthetic resin grains (hereinafter referred to as“synthetic resin grains (e)”) were compounded and mixed with thesynthetic resin grains (a) and (b) in a prescribed proportion. Then,they were blown into the blast furnace in the same manner as in theabove examples (Comparative Example).

The properties of the sheet-shaped synthetic resin materials before andafter the granulation processing out of the waste synthetic resinmaterials used for the respective tests are shown in Table 10.

TABLE 10 Example 1 Example 2 Comparative Example Before Shape ofsynthetic Sheet-shaped Sheet-shaped Sheet-shaped granulation resinsprocessing Material PET resin PET resin PET resin Thickness 0.5 mm 0.5mm 0.5 mm Granulating method Melting.solidification and Crushing into 6mm or Only crushing into 6 granulation processing less (provided that mmor less after crushing into 6 mm or mixing with other resin less grains(b) later) Dimensions Brain diameter 1.5 mm or less 6 mm or less × 6 mmor less × after granulation Thickness — 0.5 mm 0.5 mm processing Massivegrains Material — PE resin — (b) mixed Maximum size — 3.2 mm — (graindiameter) Mixing ratio — PET:PE = 2:1 — Time of stopping blowing due to0.0 0.0 4.2 delivering trouble (hr/d)

In every test, sheet-shaped PET resins which were separated in the step(P) and had the same shape and a thickness of 0.5 mm were used as thesheet-shaped synthetic resin materials. In Example 1, the sheet-shapedPET resins were crushed into the small sheet pieces (C₀) of 6 mm or lessin the step (C) and then subjected to melting•solidification andgranulation processing, whereby the synthetic resin grains (c) having agrain diameter of 1.5 mm or less were prepared.

In Example 2, the sheet-shaped PET resins described above were crushedinto the small sheet pieces (C₀) of 6 mm or less in the step (D) andthen blended with massive grains (material: PE resin) which were thesynthetic resin grains (b) prepared from the solid synthetic resinmaterials in the step (B) and had a maximum size of 3.2 mm. The blendingproportion of the small sheet pieces (C₀) of the PET resin to the 3.2 mmmassive grains of the PE resin was set at 2:1. The synthetic resingrains (e) having a maximum size of 6 mm were prepared in

The Comparative Example.

Shown together in Table 10 was the time for stopping the blowing of thesynthetic resin grains due to any problems in delivering them from thetank during the period of a continuous operating test for 2 days. In theComparative Example, the stopping of the blowing into the blast furnacefor 4.2 hr/d was caused due to delivering trouble, but the problems werenot brought about at all in any of the examples. The results describedabove showed the usefulness of the present invention.

It is difficult to handle sheet-shaped synthetic resin materials inpre-processing for blowing waste synthetic resin materials into avertical metallurgical furnace such as a blast furnace, and therefore nosuitable processing methods have so far been available. However,according to the present invention, which has been constituted asdescribed above, the synthetic resin materials can be blown into avertical furnace such as a blast furnace without exerting adverseeffects on the operation thereof. Further, there can be provided agranulating process for waste synthetic resin materials, in whichsynthetic resin-made waste bottle containers can be processed in allquantities while contributing to a reduction in the blast furnace cost,and therefore industrially useful effects can be brought about.

Embodiment 4

The present inventors continued intensive investigations in order tosolve the problems described above.

As a result thereof, the present inventors have come to know thefollowing. That is, synthetic resin-made waste bottle containers have sofar been classified by material to crush the classified bottlecontainers after washing and removing labels and caps. In this case, thesynthetic resin grains are liable to be compacted to each other sincethey are of the same material and shape.

If synthetic resin-made waste bottle containers are subjected simply tocrushing processing without classifying them by material, grains havingvarious shapes are formed since the bottle containers which aredifferent in material and thickness are already present. In addition,the edges of crushed pieces are semi-molten by frictional heat incrushing and the shapes thereof are deformed in some materials.

There has been obtained the knowledge that because of the reasonsdescribed above, synthetic resin grains prepared by crushing the bottlecontainers still having labels and caps do not cause hanging in storagetanks and clogging in pipe lines. Provided that since caps are usuallymade of metals, they exert an influence on abrasion of the blades of acrusher, and therefore it is not necessarily advisable to crush thebottle containers together with the caps.

The present invention has been made based on the knowledge describedabove, and the constitution of the method for processing syntheticresin-made waste bottle containers according to the present invention ischaracterized by subjecting the synthetic resin-made waste bottlecontainers having labels thereon to crushing processing without removingthe labels and then blowing the synthetic resin grains prepared by thuscrushing the bottle containers into a vertical furnace such as a blastfurnace by means of a pneumatically feeding means.

Next, the embodiment of the present invention shall be explained withreference to the drawing.

FIG. 17 is a flow sheet showing one example of the embodiment of thepresent invention.

General dusts generated in the market are treated in a classifier 301 toclassify synthetic resin-made waste bottle containers (A) from thedusts. With respect to the classifying method, commercial equipments areavailable, and used is, for example, a pneumatic classifier in whichflowing dusts are blown off by means of an aerodynamic force making useof different flying distances of the respective dusts. The classifiedsynthetic resin-made waste bottle containers are compressed by means ofa compressing equipment 302 to increase the bulk density for the sake ofconvenience in carrying.

Then, the compressed bottle containers are subjected to prescribedpre-processing to form synthetic resin grains (B′) having a prescribedgrain diameter. That is, the compressed synthetic resin materialscarried to a pre-processing facility 303 is processed by means of acrushing and cooling equipment 304 to granulate them. In this case, thecompressed synthetic resin materials, which have been compressed aslabels are adhered on the synthetic resin-made bottle containers, arecrushed, and therefore as described above, the granulated syntheticresin materials have a shape in which drop-shaped fused grains areadhered to the end face parts of the respective grains. Since crushedpieces of metals are sometimes mixed in, iron scraps are removed bymeans of the following magnetic separator 305, and aluminum is removedby means of an Al removing equipment 305′, whereby the synthetic resingrains (B′) are prepared. They are treated in a sieving and separatingequipment 306 to control the grain diameters to a prescribed graindiameter or less, and the synthetic resin grains (B′) thus prepared arestored in a primary storage tank 307. They are fed into a pneumaticallyfeeding facility 310 via a service tank 308 by means of compressed airsupplied from an accumulator 309. The synthetic resin grains (B′) fedinto the pneumatically feeding facility 310 are transported into asecondary storage tank 311. Then, they are transferred into a blowingtank 313 via an equalizing tank 312 and blown into a blast furnace 317from the tuyere 316 via a blowing tube 315 by means of high pressure airsupplied from an accumulator 314. The blown synthetic resin grains arecombusted with the aid of high temperature hot blast 318 blown from thetuyere 316 to generate combustion heat, whereby the matters charged intothe blast furnace are heated and molten, and CO and H₂ gases aregenerated to act as a reducing agent for iron ore.

The synthetic resin grains remaining on the sieve after the sieving andseparating processing are returned to, for example, the crushing andcooling equipment to reuse them.

In the step described above, only the synthetic resin-made waste bottlecontainers separated from dusts are not necessarily used, and they maybe carried directly into a compressing equipment from super stores andconvenience stores. The facilities of from the primary storage tank 307up to the pneumatically feeding facility 310 are preferably installed inthe vicinity of the blast furnace facility to use them also asfacilities for blowing other waste synthetic resin materials into ablast furnace.

EXAMPLES

Next, the present invention shall be explained in further detail withreference to examples.

First of all, synthetic resin-made waste bottle containers wereclassified from general dusts, and a sample was taken from them forinvestigation and testing to determine a constitutional proportion bymaterial and an average calorific value. The constitutional proportionby material and the average calorific value of the synthetic resin-madewaste bottle containers are shown in Table 11.

TABLE 11 Material Proportion (wt. %) PET 66.4 PP + PE 31.8 PVC 1.6Others 0.2 Total 100.0

As can be seen from the result shown in Table 11, PET accounts for aprincipal part in terms of a material, and PP and PE follow it. Theconstitutional proportion of PVC containing halogen is as low as 2 wt %or less. The average calorific value is 6859 kcal/kg, which almostreaches the range of the calorific value of coke used in a blastfurnace.

The method of the present invention was tested in the steps shown in theflow sheet shown in FIG. 17. The synthetic resin-made waste bottlesdescribed above were compressed as the labels and the caps were adheredthereon to mold them into a rectangular parallepipedic compact havingthe dimensions of 80×80×80 cm and a bulk density of 0.3 g/cm³, and thenthe whole amount thereof were crushed and cooled to granulate them.There were removed the metallic caps by means of the magnetic separatorand aluminum by means of the Al removing equipment. Further, thegranular synthetic resin materials were treated in the sieving andseparating equipment to remove the synthetic resin grains having adiameter exceeding 6 mm. Then, the grains were blown into a practicalblast furnace from the tuyere by means of the pneumatically feedingequipment according to the flow sheet shown in FIG. 17.

Shown are the blast furnace-operating conditions during a test period inTable 12 and the conditions for blowing the synthetic resin materialsinto the blast furnace in Table 13. Continuous test operation wascarried out for 2 days in the conditions described above.

TABLE 12 Blast furnace- Iron production 9000 t/d operating conditionsCoke rate 447 kg/t-pig Blast volume 7260 Nm³/min Oxygen enrichment 4vol. % ratio Blast temperature 1200° C.

TABLE 13 Synthetic resin Blow amount of 62.5 kg/min material-blowingsynthetic resin conditions material Blow amount of 1200 Nm³/h pneumaticgas Type of pneumatic Air gas

As a result thereof, clogging in the storage tanks and the pneumaticallyfeeding pipes by the synthetic resin grains were not caused at all, andthe synthetic resin grains could stably be blown into the blast furnaceby means of the pneumatically feeding facility. Accordingly, the blastfurnace could smoothly be operated. The operating results were by nomeans inferior as compared with those obtained in conventionallyoperating a blast furnace without blowing the synthetic resin materials.PVC of 2 wt % was contained in the synthetic resin materials blown, butthe result of gas analysis showed that no dioxin was contained in blastfurnace exhaust gas.

It has been found from the test results described above that in the casewhere the synthetic resin-made bottle containers are blown into a blastfurnace after subjecting the bottle containers to pre-processing, thesynthetic resin grains having a good fluidity can be obtained bysubjecting the bottle containers to crushing and cooling processingswithout removing the labels and the caps from the bottle containers andas a result thereof, the granular synthetic resin materials can stablybe blown into the blast furnace by means of the pneumatic feedingfacility.

The present invention has been constituted as described above in amethod for processing synthetic resin-made waste bottle containers, andtherefore dumping sites for disposing them has become unnecessary.Further, in crushing and cooling processing for granulation in blowingthem into a vertical furnace such as a blast furnace, eitherclassification and separation thereof by material or distinction thereofby color is unnecessary, and the labels do not have to be removed. Inaddition, the bottles do not have to be washed. Accordingly, disposalcosts for these matters become unnecessary. Since the granular syntheticresin materials can stably be blown into a blast furnace as analternative for a part of coke, they contribute as well to a reductionin the pig iron-manufacturing cost. The present invention can providethe method for processing the synthetic resin-made waste bottlecontainers as described above to bring about industrially usefuleffects.

Embodiment 5

The present inventors continued intensive investigations in order tosolve the problems described above and obtained the following knowledge.

Shredder dusts are cotton dust-shaped and have as small bulk density as0.15 g/cm³ in the beginning of generation thereof. However, clogging inpipe lines and hanging in storage tanks can be prevented by semi-meltingand leaving them for cooling down or rapidly cooling after semi-meltingto granulate them and increase the bulk density and then pneumaticallyblowing into a vertical furnace.

On the other hand, shredder dusts are wetted while storing in an outdooryard to become massive or sticky, which makes handling thereof difficultin the course of carrying. Accordingly, the shredder dusts have to besubjected to pre-processing such as cutting or crushing beforepneumatically blowing into a vertical furnace. In this case, theshredder dusts are semi-molten by resulting frictional heat. Also, theshredder dusts are completely molten in certain cases depending on theproperties thereof in accepting them. Thus, the shredder dusts canreadily be contracted and solidified by semi-melting or melting. Suchpre-processing can prevent the pipe lines from being clogged in blowingthe shredder dusts into a vertical furnace.

The present embodiment is characterized by semi-melting or meltingshredder dusts produced in disposing automobiles and home electricappliances by frictional heat generated when cutting or crushing them,contracting and solidifying the shredder dusts thus semi-molten ormolten into a granular shape and then pneumatically feeding the shredderdusts contracted and solidified into a granular shape to blow them intoa vertical furnace.

Another embodiment is characterized by semi-melting or melting shredderdusts produced in disposing automobiles and home electric appliances byheating after cutting or crushing, contracting and solidifying theshredder dusts thus semi-molten or molten into a granular shape and thenpneumatically feeding the shredder dusts contracted and solidified intoa granular shape to blow them into a vertical furnace.

Next, the embodiments of the present invention shall be explained withreference to the drawings.

FIG. 18 is a flow chart for explaining one example of the method forfeeding shredder dusts into a vertical furnace according to the presentinvention, wherein shown are facilities and an operational flow forsubjecting to preprocessing, dusts (herein after referred to as granulardust obtained by contracting and solidifying the shredder dusts acceptedand granulating them into a prescribed grain size and then feeding theminto a vertical furnace by means of a pneumatically feeding facility. InFIG. 18, the shredder dusts (A) are carried from a stock yard (notillustrated) and crushed by means of a crushing equipment 401, and whenthe temperatures of the crushed matters are elevated, they are suitablycooled down. Depending on the shapes of the shredder dusts, they aremolded into a stick form by extruding with an extruder (not illustrated)before processing them by means of the crushing equipment 401 and thensuitably cooled down. Subsequently, the crushed dusts are loosened bymeans of a separator 402 to obtain the shredder dusts (hereinafterreferred to as “small piece dusts (A′)” from which iron scraps have beenremoved by means of a magnetic separator 403. The small piece dusts (A′)are once stored in a storage tank 413 and charged into amelting•solidifying and granulating equipment 404 via a conveyor.Provided that when the shredder dusts can be loosened only by thecrushing processing, they may not be passed through the separator 402.

The melting•solidifying and granulating equipment 404 is used forgranulating the small piece dusts (A), and depending on the shapes ofthe small piece dusts (A), they are processed through either one of tworoutes divided into P and Q. A crushing and rapidly cooling equipment404 a and a crusher 404 b are provided in the route P, and a heating andrapidly cooling equipment 404 c and a crusher 404 b are provided in theroute Q. The melting•solidifying and granulating equipment 404 is aleading equipment for contracting and solidifying the shredder dusts toincrease the bulk density and granulating them into a prescribed grainsize. Accordingly, the processing route and the equipment use manner aredetermined according to the properties of the small piece dusts (A′)staying at a middle stage and the desired shape and size of the granulardusts (a) A typical mmanner for using the melting•solidifying andgranulating equipment 404 shall be explained.

Case 1: the small piece dusts (A′) delivered from the storage tank 413are processed into the granular dusts (a) in the route P, and thefollowing routes are further available:

(1-1) the small piece dusts (A′) are processed by means of the crushingand rapidly cooling equipment 404 a to be contracted and solidified intothe granular dusts (a).

FIG. 19 is a drawing for explaining a method for contracting andsolidifying the small piece dusts (A′) into a granular shape (a) bymeans of the crushing and rapidly cooling equipment 404 a. The smallpiece dusts (A′) are fed into a rotary crusher 443 installed in acrushing chamber 442 from a charging port 441 and crushed small to besemi-molten or completely molten by frictional heat. The granulateddusts discharged from the rotary crusher 443 are rapidly cooled down bymeans of a cooling medium (for example, water spray) sprayed from anozzle 444 to be contacted and solidified into a granular shape anddischarged from a discharging port 445.

(1-2) The small piece dusts (A′) may be discharged after only crushingwithout rapidly cooling in the crushing and rapidly cooling equipment404 a of [1] described above to be contracted and solidified, and thiscontracted and solidified dust 446 may be crushed into a prescribed sizeby means of the crusher 404 b.

FIG. 20 is a schematic diagram of a method for granulating thecontracted and solidified dusts 446 by means of the crusher 404 b. Thecontracted and solidified dusts 446 are cut and crushed by means of arotary blade 447 rotating at a high rate and then cooled down in an airflow, whereby the granular dusts (a) are obtained. FIG. 20 (i) shows thecase where the temperatures of the granular dusts are elevated byfrictional heat produced in crushing but the granular dusts are notmolten at al, and FIG. 20 (ii) shows the case where the granular dustsare semi-molten by frictional heat but solidified by a cooling effectexerted by an air flow, whereby the granular dusts (a) are obtained.

(1-3) The granular dusts (a) may further be processed by means of thecrusher 404 b after processing small piece dusts (A′) into the granulardusts (a) in the manner as shown in (1-1) described above.

Case 2: the small piece dusts (A′) delivered from the storage tank 413are processed into the granular dusts (a) in the route Q, and thefollowing routes are further available:

(2-1) the small piece dusts (A′) are processed by means of the heatingand rapidly cooling equipment 404 c to be contracted and solidified intothe granular dusts (a).

FIG. 21 is a drawing for explaining a method for contracting andsolidifying the small piece dusts (A′) into a granular shape (a) bymeans of the heating and rapidly cooling equipment 404 c. The smallpiece dusts (A′) are fed onto a heating and transporting belt 450provided in a heating chamber 449 from a charging port 448, and thedusts which have been semi-molten or completely molten by heating aretransferred into an adjacent rapidly cooling chamber 451. The dusts arerapidly cooled down here by means of a cooling medium (for example,water spray) sprayed from a nozzle 452 and dispersed. They arecontracted and solidified into the granular dusts (a) and dischargedfrom a discharging port 453.

(2-2) The small piece dusts (A′) may be discharged after only heatingwithout rapidly cooling them in the heating and rapidly coolingequipment 404 c of (2-1) described above to be contracted andsolidified, and this contracted and solidified dust 454 may be crushedto a prescribed size by means of the crusher 404 b as shown in FIG. 20(i).

(2-3) The granular dusts (a) may further be processed by means of thecrusher 404 b after processing small piece dusts (A′) into the granulardusts (a) in the manner as shown in (2-1) described above.

It shall be determined based on the following ways of thinking which ofthe routes described above is selected.

In general, a method which is the most advantageous in terms of cost isthe method of (1-1) in Case 1 described above, and therefore this methodis targeted for application.

First of all, a prescribed value: D₀ mm or less shall be obtained as thetarget grain diameter of the granular dusts (a). As the rotating rateand the processing time of the rotary crusher 443 are increased, thetemperatures of the shredder dusts are elevated, and the shredder dustsare molten. On the other hand, the grain diameters of the crushed dustsare decreased as the rotating rate and the processing time of the rotarycrusher 443 are increased. In such course, the crushing conditions arecontrolled so that the grain diameters reach the target value D₀ mm orless and the dust temperatures become a temperature T₀ which is lower byprescribed value than the melting point, and when the grain diameter andthe temperatures of the dusts satisfy these conditions, the dusts arerapidly cooled down.

In the case where the dust temperatures do not reach T₀ while the graindiameter have reached D₀ mm or less, the conditions are controlled sothat the elevating rate of the dust temperatures is increased whilesuppressing an increase in the crushing rate. In contrast with this, inthe case where the grain diameter do not reach D₀ mm or less while thedust temperatures have reached T₀, the conditions are controlled so thatthe crushing rate is accelerated while suppressing the elevating rate ofthe dust temperatures.

The use of the heating and rapidly cooling equipment 404 c in the case 2is limited fundamentally to emergency such as the case where adifference between the materials in the material constitution of thesmall piece dusts (A′) is large, and a difference between the meltingtemperatures thereof is large, or the case where the crushing andrapidly cooling equipment 404 a can not be used because of under repair.

The present invention is characterized largely by that dusts which arecotton dust-shaped and have a small bulk density, such as shredder dustsare contracted and solidified and granulated by subjecting them tosuitable pre-processing as described above and then blown into avertical furnace such as a blast furnace from the tuyere. Thus, cloggingin a pipe line and hanging in a storage tank are not caused, and thevertical furnace can be operated continuously without having problems.

The granular dusts (a) are charged into the sieving and separatingequipment 405, and the grains ( through sieve) having a grain diameterof less than a prescribed value are stored in a primary storage tank 406as shown in the route R. The granular dusts (a) having a prescribedgrain diameter stored in the primary storage tank 406 are pneumaticallytransported to a pneumatically feeding equipment 408 via a service tank407. The pneumatically feeding equipment 408 comprises a secondarystorage tank 408 b in which the granular dusts (a) are prepared forfeeding, an equalizing tank 408 c, a blowing tank 408 d and apneumatically feeding accumulator 408 a. Then, the granular dusts (a)are blown into a blast furnace 412 from a blowing tube 410 disposed at atuyere 411 of the blast furnace.

On the other hand, the granular dusts having a grain diameter of theprescribed value or more remaining on the sieve in the sieving andseparating equipment 405 described above are further divided into smalllumps having a grain diameter of less than the prescribed value andlarge lumps having a grain diameter of the prescribed value or more. Thesmall lump dusts are returned to the storage tank 413, the roughlycrushing and cooling equipment 401 or the melting•solidifying andgranulating equipment 404 to reuse them. Meanwhile, the large lump dustsare joined into a raw material-charging line (not illustrated) which isan auxiliary facility of the blast furnace and charged form the top ofthe blast furnace together with coke, or charged into a coke oven,blended in a material yard or charged into a sintering furnace.

EXAMPLES

Next, the present invention shall be explained in further detail withreference to examples.

Based on the flow chart showing the process of the present inventionshown in FIG. 18, a test for blowing shredder dusts into a practicalblast furnace from the tuyere after subjecting them to pre-processingand a test operation for charging the processed shredder dusts from thetop were carried out over the period of 7 days. The operating conditionsof the blast furnace are shown in Table 14.

TABLE 14 Blast furnace- Iron production 9000 t/d operating Coke rate 447kg/t-pig conditions Blast volume 7260 Nm³/min Oxygen enrichment ratio 4vol. % Blast temperature 1200° C.

According to the flow chart shown in FIG. 18, the shredder dusts (A)were processed by means of the crusher 401. The temperatures of theshredder dusts (A) were elevated to about 120° C. by frictional heatproduced by crushing, so that the shredder dusts (A) were semi-molten,and therefore they were cooled down by water. Subsequently, they weretreated in the separator 402 and the magnetic separator 403 and thencharged into the melting•solidifying and granulating equipment 404. Themelting•solidification and granulation was carried out in the route P,and the crushed dusts which were semi-molten by processing with thecrushing and rapidly cooling equipment 404 a were rapidly cooled downand contracted and solidified into a granular shape. Further, thegranular solidified dusts were crushed by means of the crusher 404 b toobtain the granular dusts (a). Then, they were treated in the sievingand separating equipment 405, and the granular dusts having a graindiameter of 6 mm or less were stored in the primary storage tank 406.Subsequently, the granular dusts (a) were pneumatically transported tothe pneumatically feeding equipment 408 via the service tank 407 andblown into the blast furnace 412 from the tuyere 411 via the blowingtube 410. The blown granular dusts had a bulk density of 0.35 to 0.45g/cm³.

The blowing conditions of the granular dusts (a) are shown in Table 15.

TABLE 15 Shredder dust- Blow amount of synthetic 62.5 kg/min blowingresin material conditions Blow amount of pneumatic gas 1200 Nm³/h Typeof pneumatic gas Air

On the other hand, the massive dusts having a grain diameter of 50 mm ormore out of the dusts having a grain diameter exceeding 6 mm, which wereobtained by treating in the sieving and separating equipment 405 werestored in a prescribed amount and then charged from the top of the blastfurnace 412 through the raw material-charging line of the blast furnace412 together with coke. The massive dusts having grain diametersexceeding 6 mm and less than 50 mm were recycled into the roughlycrushing and cooling equipment 401.

The shredder dusts blown had a calorific value of about 3000 kcal/kg anda blown amount of 2.2% in terms of a weight ratio based on the weight ofcoke. The granulation of the shredder dusts and an increase in the bulkdensity thereof entirely prevented operating any problems such asclogging in the pipe lines by shredder dusts and hanging in the storagetanks from being brought about during the continuous operation over aperiod of 7 days, and no change in the operating results of the blastfurnace was observed as compared with those in ordinary operation.Further, analyzed were dioxin by a GC-MS method and NO_(x) bychemiluminescence to find that both were not detected in blast furnacegas.

The present invention has been constituted as described above, andtherefore clogging in the pipe lines by shredder dusts and hanging inthe tanks are prevented from being caused. In addition, the shredderdusts can be blown into a blast furnace without exerting adverse effectson the operating conditions of the furnace, and the shredder dusts canbe disposed without producing dioxin and harmful gas such as NO_(x).Thus, the method of the present invention for disposing the shredderdusts coming from waste cars and waste home electric appliances in avertical furnace brings about industrially very useful effects.

Embodiment 6

In order to eliminate the foregoing problems, the present inventors havemade many studies with the following findings. To begin with, inspectionof the combustion zone out of a peep hole for the tuyere has revealedthat upon blowing in the furnace, a synthetic resin material having alarge particle diameter remains combustibly swirled in the combustionzone for a prolonged period of time until the resin particles becomerather fine, after which the resin material flies outside such zone. Incontrast to the synthetic resin material, coal, namely finely grainedcoal, gets immediately decomposed with heat and finely grained whileliberating its volatile components, eventually flying outside thecombustion zone.

Thus, when blown into the furnace out of the tuyere, the synthetic resinmaterial and coal show their respective different behaviors in thecombustion zone. In regard to the resin material, it has now been foundthat if the particle diameters are so formed as to delay flying of theresulting resin particles out of a combustion zone, improvedcombustibility can be attained.

As a result, the present inventors have found the following facets.

In general, end velocity commonly so called is taken to denote theparticle velocity in which the screwing force applied to particlesmoving in a fluid in a gravitational field or a centrifugal field getsbalanced with the resisting force of those particles. While the endvelocity of a synthetic resin material blown out of a tuyere into acombustion zone is being maintained sufficiently higher than the flowrate of gas discharged out of that zone, the resin material does not flyoutside the combustion zone and hence remains still circulated in thatzone so that the resin material is made sufficiently combustible with ahigh combustion ratio.

The present invention has been completed based on the aforementionedfindings. The invention pertains to a method wherein pig iron isproduced in a vertical furnace by use of a synthetic resin materialblown as a heat source out of a tuyere into the furnace, characterizedin that such resin material has a particle diameter capable of affordinga higher end velocity than the flow rate of gas coming out of acombustion zone. Such specific particle diameter is hereunder referredto as “critical particle diameter”.

Here, the critical particle diameter should preferably be decided fromthe following empirical steps; that is, [1] the flow rate of gasdischarged out of a combustion zone is computed depending on theoperating conditions of a vertical furnace used, [2] the end velocity ofa synthetic resin material in a combustion zone is decided with resortto the physical characteristics (including particle diameters) of theresin material and to the physical characteristics of the combustionzone, and [3] a certain empirical equation is solved which is needed toevidence that such end velocity is greater than the rate of gas flow.

Next, one preferred embodiment of the present invention will bedescribed with reference to the drawings.

FIG. 22 is a schematic perspective view taken to explain the interior ofa vertical furnace wherein a combustion zone has been defined forwardlyof a tuyere by charging out of a furnace top heat sources such as ironore, scrap and the like and coke, by blowing from the tuyere a givenoxygen-rich air and a selected synthetic resin material, andsubsequently by burning the coke coming down at the tuyere location,thereby bringing such resin material into combustible condition.

In FIG. 22, designated at 501 is an inner wall of a vertical furnacebody, at 502 a synthetic resin material, at 503 a tuyere and at 504 acombustion zone. With further respect to the combustion zone 504, D_(R)refers to the breadth of such zone, H_(R) to the height of such zone,V_(G) to the rate of gas flow in a vertical direction at a terminal endof such zone and D_(R) to the diameter of the tuyere. The width of thethe combustion zone is not shown in this figure which, however, has alength W_(R) in a direction perpendicular to the plane of the figure.

In this embodiment, the flow rate of gas V_(G) discharged in a verticaldirection out of the combustion zone (hereunder referred to as “flowrate of gas in a vertical direction at a terminal end of the combustionzone”) and the end velocity V_(p) of a synthetic resin material in thecombustion zone are decided as indicated below.

(1) Flow Rate of Gas in Vertical Direction at Terminal End of CombustionZone

The flow rate of gas V_(G) in a vertical direction at a terminal end ofthe combustion zone is decided by computing the cross-sectional area ofsuch zone from the width W_(R) of and the height H_(R) of such zone andfurther by calculating the void of coke filled.

The length D_(R) of, the width W_(R) of and the height H_(R) of thecombustion zone are represented, respectively, by the equations (1), (2)and (3) below.

D _(R) /D _(T) =C(ρ_(g) /εb ³ρ_(p))^(½)·(U/(gD_(pc))^(½)  (1)

W _(R) /D _(R)=2 cot 30(1+kD _(R) /D _(T))^(½)  (2)

(H _(R) /D _(R))(D_(R) /D _(T))=Kε _(p) ^({fraction (3/2)})  (3)

where D_(R): length of combustion zone (m)

W_(R): width of combustion zone (m)

H_(R): height of combustion zone (m)

D_(T): diameter of tuyere (m)

D_(pc): diameter of coke charged (m)

ρ_(g): density of blown gas (kg/m³)

ρ_(p): apparent density of coke (kg/m³)

ε_(b): void of coke charged when filling (−)

g: gravity acceleration (m/sec³)

U: gas flow at tuyere tip (m/sec)

C: constant

K: constant

k: constant as to spread angle of jet

The flow rate of gas V_(G) in a vertical direction at a terminal end ofthe combustion zone can be decided by the following equation (4) withthe use of W_(R), H_(R) and ε decided from the equations (1) to (3).

V _(G) ={Q(273+T _(B))/293}×{1/(1+P _(B))}×[1/(W_(R) +H_(R))/4)²π]×(1/ε^(⅔))  (4)

where

Q: blast volume (Nm³/sec)

T_(B): blast temperature (° C.)

P_(B): blast pressure (atm)

(2) End Velocity of Synthetic Resin Material in Combustion Zone

The end velocity VP (m/sec), i.e., the particle velocity in which thescrewing force of particles of a synthetic resin material in acombustion zone positioned forwardly of a tuyere at a lower portion of avertical furnace gets balanced with the resisting force applied to thoseparticles, can be computed by the following equations (5-1) and (5-2)with the use of the temperature, gas density, gas viscosity and pressurein the combustion zone and also of the particle diameter and particledensity of a synthetic resin material selected.

In the case of 2<Re<500:

V _(p)={4g ²(ρ_(p1)−ρ)² D _(p) ³/225/μ/ρ}^(⅓)  (5-1)

In the case of 500≦Re<10⁵:

V _(p)={3.03 g (ρ_(p1)−ρ)D _(p)/ρ}^(½)  (5-2)

where

Re: Reynolds number=D_(p)V_(p)ρ/μ

V_(p): end velocity of synthetic resin material (m/sec)

ρ_(p1): particle density of synthetic resin material (kg/m³)

ρ: gas density in combustion zone (kg/m3)

D_(p): particle diameter of synthetic resin material (m)

μ: gas viscosity in combustion zone (N/m)

g: gravity acceleration (m/sec³)

Accordingly, the critical particle diameter, wherein the particles ofthe synthetic resin material are prevented from flying outside thecombustion zone at a location situated forwardly of the tuyere, can bedecided by solving a given equation in terms of the particle diameterD_(p) of the resin material, in which equation the numerical value ofthe end velocity V_(p) computed from the equation (5-1) above or or theequation (5-2) above is defined to be greater than that of the flow rateof gas V_(G) in a vertical direction at a terminal end of the combustionzone computed from the equation (4) above.

On the other hand, it is preferred that the upper limit in particlediameters of the synthetic resin material be below half the internaldiameter of transport pipings with adverse clogging of the pipings takenin view.

Suitable synthetic resin materials may be hydrocarbon comounds of apolymeric class such as polyethylene, polypropylene, polystyrene and soon. No particular restriction is placed on the kind of polymerichydrocarbon compounds.

Examples

With reference to several examples as regards combustion testing in acombustion zone positioned forwardly of a tuyere and also to thedrawings, the present invention will be described hereunder.

FIG. 23 is a schematic view, taken vertically cross-sectionally, of acombustion testing apparatus equipped with a vertical furnace used forcombustion testing according to the present invention. In this figure,the reference numeral 503 refers to a tuyere, 504 to a combustion zone,505 to a coke hopper, 506 to a synthetic resin material hopper, 507 to ablast air, 508 to a coke-filled layer, 509 to a counter rod and 510 to acombustion gas. This test apparatus has been modeled after a blastfurnace on a commercial basis.

Table 16 lists major conditions for combustion testing conducted by theuse of the abobe test apparatus.

TABLE 16 Blast volume (Nm³/hr) 350 Blast temp. (° C.) 1200 Blast gasanalysis (vol. %) O₂ 77 N₂ 23 Tuyere nose gas flow velocity (m/sec) 145Coke particle diameter (mm) 20 to 30 Void ratio upon charging coke (-)0.6 Quantity of blown synthetic resin material (kg/hr) 30 Syntheticresin material analysis (wt. %) C 84 H 14

Coke having a particle diameter of 20 to 30 mm and supplied from a cokehopper 505 was charged into a furnace from a top thereof and thenadjusted in its height of charge with a counter rod 509 such that thevoid was set at 0.6. Individually, from a tuyere 503, a blast air of1,200° C. was blown into the furnace in a blast volume of 350 Nm³/hr andalso a synthetic resin material transported from a hopper 506 for suchresin material. The resin material was blown in an amount of 30 kg/hr,which amount was reduced to be equilavent to an amount of 90 kg/t offuel (blast fuel ratio) required for 1 ton of pig iron to be produced ina blast furnace. The flow rate of gas at a tuyere tip was computed to be145 m/sec. Thus, the coke contained in a coke-filled layer 508 and theblown material were allowed to be vigorously combustible so that acombustion zone 504 was defined forwardly of the tuyere 503.

The following test [1] was first performed.

[1]: Under the test conditions, the diameter of the tuyere 503 wasmaintained constant at 65 mm, and the particle diameters (hereunderindicated by way of certain typical particle diameters) of the syntheticresin material were varied in a range from 0.6 to 10 mm. In this way,combustion was tested to determine combustion ratios.

The typical particle diameters of the resin material were defined byarithmetic mean values (hereinbelow in like manner).

The combustion ratio α was defined by the equation (6) below, wherebycombustion ratios α were calculated (hereinbelow in like manner).

α=(A−B)β/C  (6)

where A: consumption of coke (kg/hr) without synthetic resin materialblown in

B: consumption of coke (kg/hr) with synthetic resin material blown in

β: carbon content in coke

C: carbon content (kg/hr) in blown synthetic resin material

Portions of the synthetic resin material having failed to becomecombustible in the combustion zone decompose, at a region above suchzone, into constituent hydrocarbons such as ethane, ethylene, ethylene,propylene or the like. For this reason, the combustion ratio wasdetermined separately from the content of hydrocarbons in waste gascollected at an upper part of the furnace was compared to that obtainedfrom the equation (5) (hereinbelow in like manner).

The combustion ratios of the synthetic resin material relative to thetypical particle diameters thereof, obtained in Test [1] above, areshown in Table 17. The relationship between the combustion ratios andthe typical particle diameters are shown in FIG. 24.

TABLE 17 Typical particle dia. of Combustion ratio of synthetic resinmaterial (mm) synthetic resin material (-) Example 1 10 0.96 Example 2 60.95 Example 3 4 0.91 Example 4 3 0.89 Example 5 1.5 0.74 Example 6 20.63 Example 7 0.8 0.88 Example 8 .6 0.94

The flow rate of gas in a vertical direction at a terminal end of thecombustion zone, which was computed from the combustion testingconditions of [1], was determined to be 7.6 m/sec from the equation (4)above. The critical particle diameter for protecting flying outside thecombustion zone was determined to be about 2.4 mm with use of the endvelocity of the particles of the resin material obtained from theequation (5-2) above.

On the other hand, FIG. 24 shows a combustion ratio of 0.73 in the caseof blowing of a synthetic resin having a typical particle diameter of2.5 mm.

In FIG. 24, the combustion ratio is extremely small when the typicalparticle diameter is in the vicinity of 2.0 mm. This would presumably bedue to the fact that typical particle diameters below about 2.0 mm leadto increased flying, thus resulting in reduced combustion ratio, andmoreover, invite increased specific surface area, hence increasedcombustion rate. From practical points of view, however, smaller typicalparticle diameters of a synthetic resin material involve higher crushingcost and lower crushing yield.

Similar reasoning applies to the combustion ratios calculated from thehydrocarbon contents in waste gas collected at an upper part of thefurnace.

The following test [2] was then conducted. [2]: Under the testconditions of Table 16, the particle diameter of the synthetic resinmaterial was maintained constant at 2.5 mm, and the diameters of thetuyere were varied in a range from 45 to 120 mm. In this way, combustionwas tested to determine combustion ratios.

The results obtained in Test [2] are shown in Table 18. Namely, listedare the flow rates of gas in a vertical direction at a terminal end ofthe combustion zone and the combustion ratios of the synthetic resinmaterial which were decided when the tuyere diameters were fixed at thegiven levels. The relationship between the flow rates of gas in avertical direction at a terminal end of the combustion zone thecombustion ratios are shown in FIG. 25.

TABLE 18 Vertical gas flow Degree of Tuyere diameter velocity at end ofburn-up (mm) combustion zone (m/sec) (-) Example 9 100 4.8 0.93 Example10 120 4.0 0.96 Example 11 80 6.1 0.86 Example 12 65 7.6 0.77Comparative 60 8.2 0.61 Example 1 Comparative 50 10.0 0.54 Example 2Comparative 45 11.2 0.50 Example 3

The end velocity of the synthetic resin material was determined to be7.9 m/sec which was decided with a typical particle diameter of 2.5 mmof the resin material under the conditions of Test [2]. In FIG. 25, whenthe flow rate of gas in a vertical direction at a terminal end of in thecombustion zone is 7.9 m/sec as was in the case with the end velocitydetermined above, the combustion ratio of the resin material is about0.7. It is observed that when the flow rate of gas in a verticaldirection at a terminal end of in the combustion zone is lower than 7.9m/sec, the combustion ratio of the resin material is higher than 0.7 andthat when the flow rate of gas in a vertical direction at a terminal endof in the combustion zone is higher than 7.9 m/sec, the combustion ratioof the resin material is lower than 0.7.

As is clear clear from this test, there is strongly correlative betweenthe flow rates of gas in a vertical direction at a terminal end of inthe combustion zone in which the synthetic resin material is free offlying and the combustion ratios.

With the present invention constructed above, synthetic resin materialscan be blown, as a heat source for use in a vertical furnace in pig ironproduction, in the form of lumps without the need for pulverization.Further, an enhanced combustion ratio is feasible with saved coal andcoke. This invention also enables the use of synthetic resin materialsthat require disposal by incineration and reclamation, thus contributingto a great solution to environmental problems and providing noticeableindustrial significance.

Embodiment 7

FIG. 26 illustrates an embodiment of the apparatus for blowing asynthetic resin material of the present invention.

The apparatus for blowing a synthetic resin material of the presentinvention comprises a processing line X which receives synthetic resins(A) mainly comprising film-shaped synthetic resins and processes thesame into a granular synthetic resin material, a processing line Y whichreceives synthetic resins (B) other than the foregoing synthetic resins(A) and processes the same into a granular synthetic resin material, aprimary storage silo 601 into which the granular synthetic resinmaterials obtained in these processing lines X and Y are charged, and ablowing station Z which pneumatically supplies the granular syntheticresin materials supplied from this primary silo 601 to a blowing portsuch as a tuyere portion of a blast furnace (the description hereafterwill be based on a case where the “blowing port” is the tuyere portionof the blast furnace).

The foregoing processing lines X and Y receive synthetic resins to beused as a fuel as classified into synthetic resins (A) mainly comprisingfilm-shaped synthetic resins and synthetic resins (B) other than theabove (i.e., mainly comprising lumpy synthetic resins), and processthese synthetic resins into granular synthetic resin materials throughsteps suitable for the individual resins. For this purpose, theprocessing line X has a granulating/solidifying unit which processes thesynthetic resins (A) into a volume-reduced and solidified granularsynthetic resin material through solidification of the synthetic resins(A) melted or semi-melted by heat. The processing line Y has on theother hand a primary crusher with or without additional crushers forcrushing the synthetic resins (B).

The construction of the apparatus of the present invention will bedescribed below with reference to FIG. 26. The processing line X has,sequentially from the entry side, a crusher 602 provided as required forcrushing (or rough-crushing) the synthetic resins (A), agranulating/solidifying unit 603 for processing the synthetic resins (A)into a volume-reduced granular synthetic resin material (a), and a sieve604 (for example, a vibrating sieve) for sieving the granular syntheticresin material (a). The synthetic resins (A) are transferred by transfermeans 605 from the foregoing crusher 602 to the granulating/solidifyingunit 603, and by another transfer means 606 from thegranulating/solidifying means 603 to the sieve 604. These transfer means605 and 606 usually comprise transfer conveyors or gravity-chuting typetransfer ducts or transfer pipes. A magnetic separator 630 (attractingscrap by means of a magnet for removal) is provided for removal of scrapin the middle of the transfer means 605. When such a magnetic separator630 is provided, the transfer means 605 comprises a transfer conveyor ingeneral.

The granular synthetic resin material (a) having a smaller particlediameter after sieving through the sieve 604 is transferred by transfermeans 607 to a primary storage silo 601. In this embodiment, thetransfer means 607 comprises a pneumatic pipe and a fan 608 provided inthe middle thereof. The transfer means 607 may as required be a transferconveyor or a gravity-chuting type transfer duct or a transfer pipe asin the transfer means 605 and 606. The synthetic resin material having alarger particle diameter after sieving through the sieve 604 is broughtback by transfer means 609 to the transfer means 605 on the entry sideof the foregoing granulating/solidifying unit 603 and charged again intothe granulating/solidifying unit 603. The transfer means 609 as wellcomprises a pneumatic pipe and a fan 608 provided in the middle thereof,or may comprise a transfer conveyor or the like as required.

This coarse granular synthetic resin material may be sent back to anyarbitrary position: for example, between the granulating/solidifyingunit 603 and the magnetic separator 630, or on the entry side of thecrusher 602 (usually, the transfer line). It may as required be suppliedto the processing line Y. When supplying the same to the processing lineY, for example, it may be supplied to any arbitrary position on theentry side of the primary crusher 610, between the primary crusher 610and the secondary crusher 611, between the secondary crusher 611 and asorter 612, or between the sorter 612 and the milling unit 613 (usually,the transfer line). The coarse granular synthetic resin material may beremoved from the system, and charged directly into another process (forexample, top-charging into a blast furnace or a scrap melting furnace,or direct charing into a coke oven or a sintering machine).

When the synthetic resins (A) are crushed by the granulating/solidifyingunit 603 described later, crushing by the above-mentioned crusher 602 isnot always necessary, not requiring the crusher 602.

The foregoing granulating/solidifying unit 603 has a mechanism whichperforms a volume-reducing solidification-granulation treatment of thesynthetic resins (A) by, for example, any of the following methods ( 1)to ( 3):

( 1) A method of heating the synthetic resins (A) for melting, thencooling the resultant melt for solidification, and cutting or millingthe synthetic resin material after solidification;

( 2) A method of cutting or crushing the synthetic resins (A) (cuttingor crushing may be accomplished, not in the granulating/solidifyingunit, but in the foregoing crusher 602), semi-melting the thus cut orcrushed synthetic resin material through heating or by means offrictional heat resulting from the above cutting or crushing, andcausing the semi-molten synthetic resin material to contract andsolidify into a granular form, or milling the synthetic resin materialafter contraction and solidification, thereby obtaining a granularsynthetic resin material (a);

(3) A method, as a variation of the above method (2), of cutting thesynthetic resins (A) with a rotary knife edge rotating at a high speed,or crushing the same, semi-melting the synthetic resin material byfrictional heat produced by such cutting or crushing, and then, causingcontraction and solidification of the semi-molten synthetic resinmaterial by rapid cooling through water sprinkling or the like into agranular form or milling the same with the above rotary knife edgesimultaneously with contraction and solidification, thereby obtainingthe granular synthetic resin material (a).

A typical example of the apparatus based on the method (1) comprisesmeans for completely melting the synthetic resins (A), extruding meansfor extrusion-forming the molten synthetic resins into a linear form orthe like, and cutting means for cutting the thus extrusion-formedsynthetic resin material. Any of various other processing methods mayalso be adopted.

In contrast to this, the methods (2) and (3) comprise, not completelymelting the synthetic resins (A), causing contraction and solidificationthereof through rapid cooling from semi-molten state by spraying acooling fluid (water or a cooling gas) into a granular form, or millingthe same after contraction and solidification into a granular form,thereby obtaining a granular synthetic resin material (a). According tothe present inventors' findings, the granular synthetic resin material(a) obtained by the use of the apparatus based on the method (2) or (3)(particularly (3)) are very excellent in fluidity and transferability ascompared not only with milled film-shaped synthetic resin material, butalso with milled lumpy synthetic resin material, and very excellent incombustion property. Further, it is possible to largely improvetransferability and combustion property of the synthetic resin materialas a whole by using the same in mixture with a milled lumpy syntheticresin material. It is therefore most suitable to use agranulating/solidifying unit 603 based on the method (2) or (3) above inthe fuel blowing apparatus of the present invention.

FIG. 28 illustrates a typical configuration of thegranulating/solidifying unit 603 performing continuous processing ofgranular contraction and solidification orcontraction-solidification-granulation based on the method (2) above.The granulating/solidifying unit 603 has, sequentially from the entryside of the synthetic resins, a crusher 639, a volume-reducingsolidifying unit 640 and a milling unit 641 which is provided asrequired. The volume-reducing solidifying unit 640 has, from the entryside, a heating chamber 642 and a cooling chamber 643 as well as atransfer unit 644 (such as a transfer conveyor) for continuouslytransferring the synthetic resins through these heating chamber 642 andcooling chamber 643.

According to this granulating/solidifying unit 603, the synthetic resins(A) are crushed by the crusher 639, and then charged into thevolume-reducing solidifying unit 640. In the volume-reducing solidifyingunit 640, the synthetic resins (A) are semi-melted by heat (by gasheating, indirect gas heating or electric heating) in the heatingchamber 642 while being continuously transferred by the transfer unit644 through the heating chamber 642 and the following cooling chamber643, and then contract and solidify through rapid cooling in the coolingchamber 643 by means of water spray. It is possible to cause thesynthetic resin material to contract and solidify in a granular form byappropriately selecting a form of crushing of the synthetic resins (A)and a condition of charging thereof into the heating chamber, and thus agranular synthetic resin material (a) is available in the state ofcontraction and solidification by the application of this method.

According to the method of not causing all or part of the syntheticresin material to contract or solidify, on the other hand, the syntheticresin material after contraction and solidification is charged from thevolume-reducing solidifying unit 640 into the milling unit 641, and agranular synthetic resin material (a) is available through milling intoa granular form in this milling unit 641.

The thus obtained granular synthetic resin material (a), which is madeby causing the crushed film-shaped synthetic resin material to contractand solidify from a semi-molten state into a granular form, or bymilling the same after contraction and solidification, is relativelyporous as compared with a crushed lumpy synthetic resin material and hasa large specific surface area. It has a rounded shape as a whole, not anangular shape as a crushed lumpy synthetic resin material, leading toexcellent combustion property and fluidity.

FIG. 29 shows an outline of the construction of the apparatus based onthe method (3) above, and FIG. 30 schematically illustrates theprinciple of granular contraction-solidification orcontraction/solidification-granulation treatment in this apparatus.

This granulating/solidifying unit 603 comprises a tank 645 into whichthe synthetic resins (A) are charged, one or more rotary knife edges 646arranged on the bottom in this tank 645, and rapid cooling means 647 forblowing or spraying a cooling fluid (a liquid such as water or a gas)into the tank 645. According to this granulating/solidifying unit 603, agranular synthetic resin material (a) is obtained by cutting or crushingthe synthetic resins (A) charged into the tank 645 with the rotary knifeedges 646 rotating at a high speed, semi-melting the synthetic resinmaterial by frictional heat produced by this cutting or crushing, andthen, causing the semi-molten synthetic resin material to contract andsolidify through rapid cooling from the above-mentioned temperature bymeans of water spray from the rapid cooling means 647 into a granularform, or applying a milling treatment with the foregoing rotary knifeedges 646 simultaneously with contraction and solidification.

The granular synthetic resin material (a) thus obtained comprises acrushed film-shaped synthetic resin material caused to granularlycontract and solidify from a semi-molten state or milled aftercontraction and solidification. As compared with a crushed lumpysynthetic resin material, therefore, it has relatively porous propertieswith a large specific surface area, exhibiting a rounded shape as awhole, not an angular shape as the crushed lumpy synthetic resinmaterial, resulting in excellent combustion property and fluidity.

This apparatus is to carry out all of crushing (or cutting) of thesynthetic resin material, semi-melting, and milling treatment aftercontraction and solidification (milling is not however required whencontraction and solidification are caused by rapid cooling) in a batchmanner with the use of a rotary knife edge 646 rotating at a high speed.Therefore, a series of processing steps of “crushing (orcutting)→semi-melting→granular contraction/solidification” or “crushing(or cutting)→semi-melting→contraction and solidification by rapidcooling” are accomplished rapidly within a short period of time.Furthermore, because the synthetic resin material is semi-melted duringcrushing (cutting) by the rotary knife edge 646 and high-speed stirringand rapidly cooled from this state, there is available a granularsynthetic resin material (a) preferable in terms of specific surfacearea and grain shape. Since crushing (or cutting), semi-melting andmilling after contraction and solidification are accomplished solelyunder the action of the rotary knife edge 646, moreover, this methodprovides advantages in equipment cost as well as in operating cost.

In the apparatus based on the method (3) as well, it is possible tocause contraction and solidification of the synthetic resin materialinto a granular form by appropriately selecting a manner of crushing ofthe synthetic resins (A) and the charging condition thereof relative tothe rotary knife edge. The granular synthetic resin material (a) is thusavailable in the state of contraction and solidification, in this case,substantially without a milling step by means of the rotary knife edge646 after contraction and solidification When all or part of thesynthetic resin material is not caused to contract and solidify in agranular form, on the other hand, a granular synthetic resin material(a) is available, as described above, through a milling step with therotary knife edge 646.

The temperature for semi-melting the synthetic resins (A) in the methods(2) and (3) above varies to some extent, depending upon the kind and theshape of the synthetic resins: in terms of the material quality alone,for example, it is within a range of from about 105 to 115° C. forlow-density polyethylene, and about 128° C. for medium to low-densitypolyethylene. An appropriate temperature for semi-melting is selected inresponse to the kind, the ratio and the form of synthetic resinscontained in the synthetic resins (A).

The foregoing processing line Y has, on the other hand, a primarycrusher 610 for roughly crushing the synthetic resins (B), a secondarycrusher 611 for further finely crushing the synthetic resins (B), aselector 612 for removing foreign matters such as metals, sand and earthfrom the crushed synthetic resins (B), and a milling unit 613 formilling the synthetic resins (B) after removal of foreign matters into afinal particle diameter to obtain a granular synthetic resin material(b).

The synthetic resins (B) are transferred from the primary crusher 610 tothe secondary crusher 611 by transfer means 614, and from the secondarycrusher 611 to the selector 612 by transfer means 615, respectively.These transfer means 614 and 615 usually comprise transfer conveyor, orgravity-chuting type ducts, or transfer pipes. A magnetic separator 630(attracting scrap and the like with a magnet for removal) for removingscrap is provided in the middle of the transfer means 614. When such amagnetic separator 630 is provided, the transfer means 614 usuallycomprises a transfer conveyor.

The synthetic resins (B) or the granular synthetic resin material (b) istransferred from the selector 612 to the milling unit 613 by transfermeans 616, and from the milling unit 613 to the primary storage silo 601by transfer means 617, respectively. In the present configuration, thetransfer means 616 and 617 comprise pneumatic feed pipes and fans 608provided in the middle thereof, or may as required comprise transferducts, or gravity-chuting type transfer ducts or transfer pipes, as inthe case of the transfer means 614 and 615.

Between the foregoing primary silo 61 and the blowing station Z, thereare provided, sequentially from the upstream, a service tank 619receiving and temporarily storing the granular synthetic resin materialsupplied from the primary silo 601, and a lift tank 621 receiving thegranular synthetic resin material supplied from this service tank 619and pneumatically supplying the same to the blowing station Z.

The granular synthetic resin material is supplied from the primarystorage silo 601 to the service station 619 by transfer means 618. Thistransfer means 618 comprises, for example, a constant-volume cuttingunit and a transfer conveyor, or a gravity-chuting type transfer duct,or a transfer pipe. The granular synthetic resin material is transferredfrom the service tank 619 to the lift tank 621 by transfer means 620.This transfer means 620 comprises a gravity-chuting type transfer pipe,and a shut-off valve 638 for supply and stoppage of the granularsynthetic resin material and holding the gas pressure in the lift tankis provided in the middle of this transfer pipe.

An air supply pipe 637 from an accumulator 629 is connected to theabove-mentioned lift tank 621, and pneumatic feeding air is supplied.The granular synthetic resin material in the lift tank 621 is suppliedby this pneumatic feeding air through a pneumatic feed pipe 622 to theblowing station Z. The amount of pneumatically fed granular syntheticresin material is controlled by means of the pressure of pneumatic feedair supplied to the lift tank.

The blowing station Z has a multi-stage tank for permitting continuoussupply of the granular synthetic resin material to the blast furnacetuyere portion. In this example of configuration, there are provided,sequentially from the upstream, a secondary storage silo 623, anequalizing tank 624 and a blowing tank 625, and the foregoing pneumaticfeed pipe 622 is connected to the secondary storage silo 623. Thegranular synthetic resin material is supplied from the secondary storagesilo 623 to the equalizing tank 624 by transfer means 631, and from theequalizing tank 624 to the blowing tank 625 by transfer means 632,respectively. These transfer means 631 and 632 comprise gravity-chutingtype transfer pipes, and shut-off valves 633 and 634 for supply andstoppage of the granular synthetic resin material and holding the gaspressure in the equalizing tank 624 and the blowing tank 625 areprovided in the middle of these transfer means.

The granular synthetic resin material is pneumatically supplied from theabove-mentioned blowing tank 625 to the tuyere portion 628 of the blastfurnace BF through the pneumatic feed pipe 626 and pneumatic branchpipes 627 communicating to the individual tuyeres (in the drawing, 636is a distributor to the individual pneumatic branch pipes 627). Afluidizer 635 for mixing the granular synthetic resin materialdischarged from the tank and fluidizing the mixture is provided at aposition on the exit side of the blowing tank of the pneumatic feed pipe626. This fluidizer 635 has a function of supply and stoppage of thegranular synthetic resin material. An air supply pipe 637 from theaccumulator 629 is connected to the pneumatic feed pipe 626 to supplypneumatic air. The amount of pneumatic air for the granular syntheticresin material from the blowing tank 625 is controlled by adjusting thepressure in the blowing tank 625 by means, for example, of pressurizingmeans not shown, and as required, by adjusting the flow rate ofpneumatic gas from the accumulator 629.

FIGS. 31 and 32 illustrate other examples of configuration of theblowing station Z, respectively. Any of these blowing stations Z has noequalizing tank as shown in FIG. 26, but has a plurality of secondarystorage silo blowing tanks or blowing tanks arranged in parallel topermit continuous supply of the granular synthetic resin material to theblast furnace tuyere portion.

In the blowing station Z shown in FIG. 31, secondary storage silos 623 aand 623 b are arranged in parallel with blowing tanks 625 a and 625 b,respectively, to permit appropriately branched charging of the granularsynthetic resin material through a distributor 648 provided in thepneumatic feed pipe 622 to the secondary storage silos 623 a and 623 b.The granular synthetic resin material is supplied from the secondarystorage silos 623 a and 623 b to the blowing tanks 625 a and 625 b bytransfer means 649 a and 649 b, respectively. These transfer means 649 aand 649 b comprise gravity-chuting type transfer pipes, and shut-offvalves 650 a and 650 b for supply and stoppage of the granular syntheticresin material and for holding the gas pressure in the blowing tanks areprovided in the middle thereof. Fluidizers 651 a and 651 b having thesame functions as those of the fluidizer 635 shown in FIG. 26 areprovided at positions of the pneumatic branch pipes 860 a and 860 bconnected to the blowing tanks 625 a and 625 b, respectively, on thetank exit side.

In the blowing station Z shown in FIG. 31, three or more sets ofsecondary storage silo blowing tanks may be provided in parallel.

In the blowing station Z shown in FIG. 32, blowing tanks 625 a and 625 bare provided in parallel on the exit side of the secondary storage silo623 so as to make it possible to supply the granular synthetic resinmaterial from the secondary storage silo 623 by transfer means 652having a distributor 653 through appropriate branching to the blowingtanks 625 a and 625 b, respectively. Shut-off valves 654 a and 654 b forsupply and stoppage of the granular synthetic resin material and forholding the gas pressure in the blowing tank are provided in the middleof branch pipes to the individual blowing tanks composing the transfermeans 652. Fluidizer shut-off valves 655 a and 655 b having the samefunctions as those of the fluidizer 635 shown in FIG. 26 are provided atpositions of the pneumatic branch pipes 860 a and 860 b connected to theblowing tanks 625 a and 625 b, respectively, on the tank exit side.

In the blowing station Z shown in FIG. 32, three or more sets of blowingtanks may be provided in parallel.

In the example of configuration shown in FIG. 26, each one magneticseparator 630 is provided in each of the processing lines X and Y,whereas a plurality of magnetic separators 630 may be arranged at aplurality of positions of each processing line.

Any crushing method may be used for the various crushers (including thecrusher 613) provided in the processing lines X and Y. Apart from thecrushing method based only on usual mechanical means, the method knownas the freeze crushing method of crushing an object in a frozen statemay be adopted.

A yard drying equipment and other incidental facilities of thebrought-in synthetic resins are usually provided on the entry side ofthe processing facilities shown in FIG. 26.

FIG. 27 shows another example of configuration of the apparatus of thepresent invention: separators 656 and 657 for separating and removingchlorine-containing macromolecular resin materials such as vinylchloride from the synthetic resins are provided in the processing linesX and Y.

More specifically, in the processing line X, a separator 656 is providedbetween the crusher 602 and the granular solidifying unit 603 toseparate and remove only chlorine-containing macromolecular resinmaterials such as vinyl chloride and vinylidene chloride from thesynthetic resins (A). Because a chlorine-containing macromolecular resinsuch as vinyl chloride has a higher specific gravity than the othersynthetic resins (specific gravity of polyethylene: 0.91-0.96; specificgravity of polypropylene: about 0.89-0.91; in contrast, specific gravityof vinyl chloride: about 1.16-1.55), chlorine-containing macromolecularresins are separated from the synthetic resins (A) by the specificgravity separation method or the centrifugal separation method using aliquid such as water for the separator 656.

The foregoing separator 656 may be arranged at any arbitrary position inthe upstream of the granular solidifying unit 603 in the processing lineX.

FIG. 33 illustrates an example of configuration of the separator 656based on the specific gravity separation method. In FIG. 33, 658 is aseparating tank filled with water, 659 a and 659 b are screens forswishing water off the synthetic resin material discharged from theseparating tank, 660 is a drier for drying the synthetic resin materialafter swishing by the screen, and 661 is a water discharge tank fordischarging water separated by the screens 659 a and 659 b.

According to this separator 656, the synthetic resins (A) are chargedinto the separating tank 658 filled with water, in which the resins areseparated into chlorine-containing macromolecular resin materials suchas vinyl chloride which precipitate in the tank and the other syntheticresin materials which float up. The separated chlorine-containingmacromolecular resin materials in precipitation are discharged outsidethe tank by appropriate discharging means, separated from water throughthe screen 659 a, and then discharged outside the system. On the otherhand, the synthetic resin materials floating up in the tank, other thanthe chlorine-containing macromolecular resin materials are dischargedoutside the tank by appropriate means, and after separation from waterthrough the screen 659 b, dried in the drier 660, and sent to the nextprocess.

FIG. 34 shows an example of configuration of the separator 656 based onthe centrifugal separation method. The separator 656 comprises a hollowand cylindrical or spindle-shaped body 662, an inner cylinder 663 havinga screw arranged rotatably in the longitudinal direction in the interiorof this body 662, and a motor 664 for rotatably driving the innercylinder. In this separator, a mixture of synthetic resin materials anda medium such as water is supplied through an end of the inner cylinder663 rotating at a high speed to the interior thereof. The mixture isdischarged to the inner space of the body 662 under the action ofcentrifugal force from an opening 665 provided substantially at thecenter in the longitudinal direction of the inner cylinder 663, and isseparated, with the specific gravity of the medium as the boundary, intoa heavy fraction having a higher specific gravity (chlorine-containingmacromolecular resins) and a light fraction having a lower specificgravity (synthetic resins other than chlorine-containing macromolecularresins). That is, only a heavy fraction of the synthetic resin materialsis accumulated on the inner wall side of the body 662, resulting in astate in which the light fraction and the heavy fraction are separatedfrom each other in a radial direction of the body 662, under the effectof centrifugal force.

In the inner cylinder 663, a screw 666 a for transferring the lightfraction is provided in a longitudinal half with the foregoing openingas an approximate boundary, and a screw 666 b for transferring the heavyfraction is provided in the other longitudinal half. These screws 666 aand 666 b have spirals turning in opposite directions, and rotation ofthe inner cylinder 663 causes the screws 666 a and 666 b to transfer thesynthetic resin material toward the body ends on the respective sides.More specifically, the synthetic resin material in the light fraction istransferred by the screw 666 a having shorter blades to an end of thebody 662 and discharged from a discharge port 667 a. On the other hand,the synthetic resin material of the heavy fraction gathered on the innerwall side of the body 662 is transferred to the other end of the body662 by the screw 666 b having blades extending to the proximity of theinner wall surface of the body 662, and discharged from a discharge port667 b. The medium such as water is discharged from the apparatus througha discharge port 668 provided substantially at the center of the body662.

According to this apparatus, it is possible to discharge the syntheticresin materials separated into the light and heavy fractions outside theapparatus with the slightest water content.

In the apparatus shown in FIG. 27, the synthetic resins (A) aretransferred from the crusher 602 to the separator 656 by transfer means605 a, and from the separator 656 to the granular solidifying unit 603by transfer means 605 b. These transfer means 605 a and 605 b usuallycomprise transfer conveyors, or gravity-chuting type transfer ducts, ortransfer pipes. A magnetic separator 630 for removing scrap is providedin the middle of the transfer means 605 a. When such a magneticseparator 630 is provided, the transfer means 605 a usually comprises atransfer conveyor.

In the processing line Y, on the other hand, a separator 657 is providedbetween the selector 612 and the crusher 613 to separate and remove onlychlorine-containing macromolecular resin materials such as vinylchloride and vinylidene chloride from the synthetic resins (B). Theconstruction and the functions of the separator 657 are the same asthose of the foregoing separator 656, thus a separate descriptionthereof is therefore omitted here. The arrangement of the separator 657in the processing line Y is not limited to that of this embodiment, butit may also be arranged at any arbitrary position in the upstream ordownstream of the crusher 613, for example, between the primary crusher610 and the secondary crusher 711, between the secondary crusher 611 andthe selector 612, or on the exit side of the crusher 613.

The synthetic resins (B) are transferred from the selector 612 to theseparator 657 by transfer means 616 a, and from the separator 657 to thecrusher 613 by transfer means 616 b, respectively. These transfer means616 a and 616 b usually comprise transfer conveyors, or gravity-chutingtype transfer ducts or transfer pipes.

All the other aspects in FIG. 27 are the same as those in FIG. 26. Thesame reference numerals are therefore assigned to the correspondingcomponents, and a detailed description thereof is omitted. Also in thisexample of the configuration shown in FIG. 27, the coarse granularsynthetic resin material as oversize through the sieve 604 may be sentback to any arbitrary position including a position, for example,between the separator 656 and the granular solidifying unit 603, betweenthe magnetic separator 630 and the separator 656, or on the entry sideof the crusher 602 (usually the transfer line), and may as required besupplied to the processing line Y. When supplying the same to theprocessing line Y, it may be supplied to any arbitrary position, forexample, on the entry side of the primary crusher 610, between theprimary crusher 610 and the secondary crusher 611, between the secondarycrusher 611 and the selector 612, or between the selector 612 and thecrusher 613 (usually the transfer line). As described above, the coarsegranular synthetic resin material may be taken out the system andcharged directly into another process (for example, top charging into ablast furnace or a scrap melting furnace, or direct charging into a cokeoven or a sintering machine).

Now, treatment of synthetic resins in the apparatus of the presentinvention and the blowing process thereof into a blast furnace will bedescribed below.

In the apparatus of the present invention, synthetic resins to be usedas a fuel as classified into synthetic resins (A) mainly comprisingfilm-shaped synthetic resin materials and other synthetic resins (B)(i.e., mainly comprising lumpy synthetic resin materials) are receivedby processing facilities, and processed into granular forms suitable asa solid fuel for blowing (or a reducing agent of iron) through differentsteps on processing lines X and Y, respectively. The synthetic resins(A) may contain synthetic resin material of other forms defective influidity or transferability such as foaming plastics, in addition to thefilm-shaped resin materials.

There is no particular limitation on the film-shaped synthetic resinmaterials. According to findings confirmed by the present inventorsthrough experiments, however, synthetic resin films having a thicknessof up to 100 μm are particularly low in fluidity and transferability.Synthetic resin films having a thickness of up to 100 μm shouldpreferably be classified as synthetic resins (A) within a classifiablerange. It is however needless to mention that the present invention isnot limited to such classification criteria: in addition to extra-thinmaterials such as polyethylene films, relatively thick synthetic resinssuch as those used in PET bottles may be included in the syntheticresins (A). Whether or not classified as synthetic resins (A) depends,in addition to thickness, upon such factors as the chemical compositionof the synthetic resin, the material (for example, composite materialscontaining or not containing substances other than synthetic resins),and the shape.

On the other hand, while the synthetic resins (B) mainly comprises lumpysynthetic resin materials such as plate-shaped ones, this is not amandatory limitation.

In summary, it suffices to take account of fluidity and transferabilityof collected synthetic resins, classify ones extremely low in fluidityor transferability in a crushed state at least such as polyethylenefilms as synthetic resins (A), and classify ones satisfactory influidity and transferability as compared with the above such as lumpyplastics as synthetic resins (B), and remaining ones as any of thesynthetic resins (A) and (B), considering fluidity and transferability.

When viewing the processing of synthetic resins and the blowing systemthereof as a whole, it is not always necessary to strictly classify allfilm-shaped synthetic resins from among synthetic resins to be suppliedas a fuel as the synthetic resins (A) and classify all lumpy syntheticresins as the synthetic resins (B). When considering the nature ofwaste, such a strict classification is practically difficult. Thesynthetic resins (A) are allowed to contain lumpy synthetic resins tosome extent and the synthetic resins (B) are allowed to containfilm-shaped synthetic resins to some extent.

In the processing line X, the synthetic resins (A) are as requiredcrushed (or rough-crushed) by the crusher 602, then charged into thegranular solidifying unit 603 by the transfer means 605, and processedinto a volume-reducing solidified granular synthetic resin material (a).Scrap mixed in the synthetic resins is removed by the magnetic separator630 in the middle of the above-mentioned transfer means 605.

In the foregoing granular solidifying unit 603, the synthetic resins (A)are subjected to a volume-reducing solidification/granulation treatmentby any of the above-mentioned methods (1) to (3), and there is availablethe granular synthetic resin material (a). The granular synthetic resinmaterial (a) obtained in the granular solidifying unit 603 is charged bythe transfer means 606 into the sieve 604 for sieving, and onlyparticles having a particle diameter of up to a prescribed level (forexample, −6 mm) are sent by the transfer means 607 to the primarystorage silo 601. Particles of the granular synthetic resin materialhaving a particle diameter of over the prescribed level are sent by thetransfer means 609 back to the transfer means 605 on the entry side ofthe granular solidifying unit 603, and are charged again into thegranular solidifying unit 603 together with the synthetic resins (A).

In the case of the apparatus shown in FIG. 32, the synthetic resins (A)are charged into the separator 656 prior to processing in the granularsolidifying unit 603, where chlorine-containing macromolecular resinmaterials such as vinyl chloride and vinylidene chloride are separatedand removed. After separation and removal of chlorine-containingmacromolecular resin materials in the separator 656, the syntheticresins (A) are charged into the granular solidifying unit 603, where thesynthetic resins (A) are processed into a volume-reducing granularsynthetic resin material (a), and then sent to the primary storage silo601 through the sieve 604.

In the processing line Y, on the other hand, the synthetic resins (B)are roughly crushed (for example, to a particle diameter of about 50 mm)in the primary crusher 610, and then charged by the transfer means 614into the secondary crusher 611 for secondary crushing (for example, to aparticle diameter of about 20 mm). From the primary-crushed syntheticresins (B), scrap mixed therein is removed by the magnetic separator 630in the middle of the above-mentioned transfer means 614.

The secondary-crushed synthetic resins (B) are charged by the transfermeans 615 into the selector 612, where foreign matters such as metals,earth and sand are separated and removed by blowing or the like. Then,the synthetic resins (B) are sent by the transfer means 616 to themilling unit 613 (tertiary crusher) for milling into a particle diameterunder a prescribed level (for example, −6 mm), thereby obtaining agranular synthetic resin material (b). This granular synthetic resinmaterial (b) is sent by the transfer means 617 to the primary storagesilo 601.

In the apparatus shown in FIG. 32, the synthetic resins (B) are charged,prior to milling in the milling unit 613, into the separator 657, wherechlorine-containing macromolecular resin materials are separated andremoved. After separation and removal of chlorine-containingmacromolecular resin materials in the separator 657, the syntheticresins (B) are sent to the milling unit 613 (tertiary crusher) formilling into a particle diameter under a prescribed level (for example,−6 mm), and then sent to the primary storage silo 601.

The mixture of the granular synthetic resin materials (a) and (b) storedin the primary storage silo 601 is supplied by the transfer means 618and 620 through the service tank 619 to the lift tank 621, pneumaticallyfed from the lift tank 621 to the blowing station Z, and charged intothe secondary storage silo 623.

In the blowing station Z, the granular synthetic resin material iscontinuously and pneumatically fed from the blowing tank 625 to thetuyere portion of the blast furnace. To carry out such continuouspneumatic feeding, the granular synthetic resin material is previouslycharged from the secondary silo 623 into the equalizing tank 624 in theclosed state of the shut-off valve 634 of the transfer means 632 betweenthe equalizing tank 624 and the blowing tank 625 (upon charging, theshut-off valve 633 of the transfer means 631 is in open state), and atthe point when the remaining amount of the granular synthetic resinmaterial in the blowing tank 625 becomes smaller, the shut-off valve 634of the transfer means 632 is opened in the closed state of the shut-offvalve 633 of the transfer means 631 to replenish the blowing tank 625with the granular synthetic resin material from the equalizing tank 624.By repeating these operations, the remaining amount of the granularsynthetic resin material in the blowing tank 625 is ensured, and thegranular synthetic resin material can be continuously and pneumaticallyfed from the blowing tank 625.

When the blowing station Z has a construction as shown in FIG. 31, thegranular synthetic resin material supplied through the pneumatic feedpipe 622 from the lift tank 621 side is appropriately distributed by thedistributor 648 to the secondary storage silos 623 a and 623 b, and theblowing tanks 625 a and 625 b are replenished with the granularsynthetic resin material from the secondary storage silos 623 a and 623b in response to the remaining amount of the granular synthetic resinmaterial in the blowing tanks 625 a and 625 b.

The granular synthetic resin material is always pneumatically suppliedfrom any of the blowing tanks 625 a and 625 b to the tuyere portion ofthe blast furnace, and the granular synthetic resin material is suppliedfrom the secondary storage silo to the other blowing tank not conductingpneumatic feeding. Upon switching between the blowing tanks 625 a and625 b conducting replenishing and pneumatic supply of the granularsynthetic resin material, the shut-off valves 650 a and 650 b of thetransfer means 649 a and 649 b between the secondary storage silos 623 aand 623 b and the blowing tanks 625 a and 625 b and the fluidizers 651 aand 651 b on the exit side of the blowing tanks 625 a and 625 b areappropriately opening/closing operated.

When the blowing station Z has a construction as shown in FIG. 32, thegranular synthetic resin material supplied through the pneumatic feedpipe 622 from the lift tank 621 side is charged into the secondarystorage tank 623, and then, appropriately distributed and charged intothe blowing tanks 625 a and 625 b by the distributor 653 provided on thetransfer means 652, in response to the remaining amount of the granularsynthetic resin material in these tanks 625 a and 625 b.

The granular synthetic resin material is always pneumatically suppliedfrom any of the blowing tanks 625 a and 625 b to the tuyere portion ofthe blast furnace, and the other blowing tank not conducting pneumaticfeed is replenished with the granular synthetic resin material from thesecondary storage silo 623. Upon switching between the blowing tank 625a and 625 b supplying and pneumatically feeding the granular syntheticresin material, the shut-off valves 654 a and 654 b of the transfermeans 652 between the secondary storage silo 623 and the blowing tanks625 a and 625 b, and the fluidizers 655 a and 655 b on the exit side ofthe blowing tanks 625 a and 625 b are appropriately opening/closingoperated.

In the blowing stations Z having constructions shown in FIGS. 31 and 32also, as described above, it is possible to continuously andpneumatically supply the granular synthetic resin material from theblowing tanks 625 a and 825 b to the tuyere portion of the blastfurnace.

Pneumatic air is supplied from the accumulator 629 through the airsupply pipe 637 to the pneumatic feed pipe 626. Under the effect of thisair, the granular synthetic resin material discharged from the blowingtanks 625, 625 a and 625 b is sent through the pneumatic feed pipe 626and the pneumatic branch pipe 627 to the plurality of tuyeres 228, andblown into the blast furnace as a fuel.

The above description has covered an example of blowing of the syntheticresin material into the tuyere portion of the blast furnace. In afurnace of any other kind as well, the synthetic resin material issimilarly supplied to the blowing portion of synthetic resin materialsuch as tuyere portion, and blown into the furnace.

The amount of supply of the synthetic resins (A) mainly comprisingfilm-shaped synthetic resins and the synthetic resins (B) comprising theother kinds of synthetic resins to the processing facilities varies withtime to some extent because of the nature as waste. When taking up arelatively short period of time (for example, from several hours toseveral tens of hours), only any one kind of synthetic resins issupplied. Therefore, synthetic resins processed and pneumatically sentto the furnace may temporarily be only any one of the combinationssynthetic resins (A)—granular synthetic resin material (a) and syntheticresins (B)—granular synthetic resin material (b). It is well possiblethat only one of granular synthetic resin materials (a) and (b) maytemporarily be pneumatically sent to the furnace for some other reason.

As described above, the granular synthetic resin material (a) obtainedthrough granular contraction/solidification orcontraction/solidification-granulation by the above-mentioned method (2)or (3) has relatively porous properties with a large specific surfacearea, and has a rounded shape as a whole, resulting in excellentcombustion property and fluidity. By mixing the same with the granularsynthetic resin material (b), it is possible to effectively improvecombustion property, fluidity and transferability of the granularsynthetic resin material as a whole supplied to the furnace. Morespecifically, in terms of combustion property, when a mixture of thegranular synthetic resin material (a) and the granular synthetic resinmaterial (b) is blown into the furnace, the granular synthetic resinmaterial (a) having an excellent combustion property is burnt quickly tocause ignition of the granular synthetic resin material (b), thuslargely improving combustion property of the granular synthetic resinmaterial as a whole blown into the furnace.

In terms of fluidity and transferability also, furthermore, inclusion ofthe granular synthetic resin material (a) excellent in fluidity andtransferability and having a rounded shape performs a function oflubricant of improving fluidity of the granular synthetic resin materialas a whole, resulting in considerable improvement of fluidity andtransferability of the entire granular synthetic resin materials.

Examples

FIGS. 36 to 38 illustrate an embodiment of the apparatus of the presentinvention.

On the entry side of the processing line X, there is provided an uprightcutter (offline) for cutting film-shaped synthetic resin materials woundinto, for example a roll shape, and separating and removing the rollcore from the film. The processing line X has, sequentially from theentry side, a supply conveyor 672 provided with a receiving hopper 671of the synthetic resins (A) at an end thereof, a plurality of granularsolidifying units 676 a and 676 b which receive the synthetic resins (A)transferred by the supply conveyor 672 through a distribution conveyor673 capable of being switched over between forward and backward andcharging conveyors 675 a and 675 b, sieves 677 a and 677 b (vibratingdischarge units) for sieving the synthetic resin material processed intoa granular form in these granular solidifying units 676 a and 676 b, anundersize conveyor 678 and a pneumatic feed pipe 679 for transferringthe granular synthetic resin material (a) having a small particlediameter as sieved by these sieves 677 a and 677 b, and a separator 698d for separating the granular synthetic resin material (a) transferredthrough the pneumatic feed pipe 679 from pneumatic air. The granularsynthetic resin material (a) separated by the separator 698 d is chargedthrough a transfer pipe into the primary storage silo 680.

In addition, the processing line X has an oversize conveyor 681 and apneumatic feed pipe 687 for receiving and transferring synthetic resinmaterial having a large particle diameter as sieved by the sieves 677 aand 677 b, and a separator 682 for separating the synthetic resinmaterial transferred by the pneumatic feed pipe 687 from the pneumaticair and charging the same again into the receiving hopper 671.

The granular solidifying units 676 a and 676 b have the sameconstruction as that described as to the example of the configurationshown in FIG. 26.

A pair of magnetic separators 674 are arranged above the distributingconveyor 673.

The processing line Y has, on the other hand, sequentially from theentry side, a supply conveyor provided with a receiving hopper 683 ofthe synthetic resins (B) at an end thereof, a primary crusher 685 forreceiving the synthetic resins (B) transferred by the supply conveyor684 and roughly crushing the same, a transfer conveyor 686 fortransferring the synthetic resins (B) rough-crushed in this primarycrusher 685 to a secondary crusher, the secondary crusher 688 receivingthe synthetic resins (B) transferred by the transfer conveyor 686 andsubjecting the same to secondary crushing, a transfer conveyor 689transferring the synthetic resins (B) crushed in this secondary crusher688 to a wind selector, the wind selector 690 for removing foreignmatters such as earth, sand and metals from the synthetic resins (B)transferred by this transfer conveyor 689, a pneumatic feed pipe 691 forpneumatically feeding the synthetic resins after removal of foreignmatters by this wind selector 690, a separator 692 for separating thesynthetic resins (B) transferred through this pneumatic feed pipe 691from pneumatic air, a plurality of cushion tanks 695 a to 695 c forreceiving the synthetic resins (B) discharged from this separator 692through distributing conveyors 693 and 694, a plurality of crushers 696a to 696 c for receiving the synthetic resins (B) supplied from theindividual cushion tanks 695 a to 695 c and crushing the same, pneumaticfeed pipes 697 a to 697 c for transferring the granular synthetic resinmaterial (b) crushed in these crushers 696 a to 696 c, and separators698 a to 698 c for separating the granular synthetic resin material (b)transferred through these pneumatic feed pipes 697 a to 697 c frompneumatic air. The granular synthetic resin material (b) separated inthese separators 698 a to 698 c is charged through the transfer pipeinto a primary storage silo 680.

In the foregoing wind selector 690, the synthetic resins (B) are chargedinto a longitudinal zigzag path 705 and air is blown into this path 705from below to above, thereby selecting and separating the syntheticresins from the other foreign matters. The synthetic resins (B), whichare light in weight, rise through the path 705 by wind force and aredischarged into the pneumatic feed pipe 691, whereas heavy foreignmatters such as earth, sand and metals drop, on the other hand, throughthe path 705 and are discharged to below the path.

The foregoing distributing conveyors 693 and 694 and the plurality ofcushion tanks 695 a to 695 c have a function of adjusting the number ofoperating crushers 696 a to 696 c and the supply amount of syntheticresins to the crushers 696 a to 696 c. For example, when the supplyamount of the synthetic resins (B) to the processing line Y isrelatively small, only some of the plurality of crushers 696 a to 696 care operated by supplying the synthetic resins (B) only to some of theplurality of cushion tanks 695 a to 695 c by means of the distributingconveyors 695 and 694. When the supply amount of the synthetic resins(B) to the processing line Y is large, on the other hand, all thecrushers 696 a o 696 c are operated by supplying the synthetic resins(B) to all the cushion tanks 695 a to 695 c by means of the distributingconveyors 693 and 694. When the supply amount of the synthetic resins(B) is excessive relative to the capacity of the crushers 696 a to 696c, furthermore, the cushion tanks 695 a to 695 c perform the role oftemporarily storing the synthetic resins (B).

Because, in the processing line Y, crushing or milling of lumpysynthetic resins is conducted, pneumatic air after transfer of thecrushed or milled synthetic resin material contains much fine dust ofsynthetic resin material. A configuration for processing such pneumaticair comprises pipings 699 and 699 a to 699 c for transferring thepneumatic air separated in the separators 692 and 698 a to 698 c to adust collector, the dust collector 700 collecting synthetic resin dustfrom the pneumatic air transferred from these pipes, and anunder-collector conveyor 701 which includes transfer means fortransferring the collected synthetic resin dust and charging the sameinto the primary storage silo 680.

A magnetic separator 674 is arranged in the middle of the foregoingtransfer conveyor 686.

A constant-volume cutter 704 is provided in the primary storage silo680: the granular synthetic resin material cut from this constant-volumecutter 704 is supplied through the transfer conveyor 702 to the servicetank 619.

As the construction in the downstream of the service tank 619 (includingthe blowing station Z) is the same as that shown in FIG. 26, the samereference numerals are assigned to the corresponding components, and adetailed description is omitted here.

In the drawing, 703 is a fan provided in each of the pneumatic feedpipes.

FIG. 39 shows another embodiment of the apparatus of the presentinvention: a secondary wind selector 706 is provided between the primarystorage silo 680 and the service tank 619 so as to permit removal offoreign matters which could not be removed by the wind selector 690 inthe upstream. The granular synthetic resin material cut from theconstant-volume cutter 704 of the primary storage silo 680 is suppliedto this secondary wind selector 706 through the transfer conveyor 702.

The basic construction of the foregoing secondary wind selector 706 isthe same as that of the above-mentioned wind selector 690. A pneumaticfeed pipe 707 for pneumatically feeding the synthetic resins (B) afterremoval of foreign matters in the secondary wind selector 706, aseparator 708 for separating the synthetic resins (B) transferredthrough this pneumatic feed pipe 707 from pneumatic air, and a transferconveyor 709 for transferring the synthetic resins (B) discharged fromthis separator 708 to the service tank 619.

In FIG. 39, 710 is a fan for pneumatic feeding.

Now, the processing steps of the synthetic resins in the apparatus ofthe above-mentioned embodiment.

The synthetic resins (A) are as required cut in an offline uprightcutter 670, then charged into the receiving hopper 671 on the entry sideof the processing line X, charged into the granular solidifying units676 a and 676 b through the supply conveyor 672, the distributingconveyor 673 and the charging conveyors 675 a and 675 b, where thesynthetic resins (A) are processed into a volume-reduced and solidifiedgranular synthetic resin material (a). Scrap mixed in the syntheticresins is removed in the middle of the foregoing distributor 673 bymeans of the magnetic separator 674.

The granular synthetic resin material (a) obtained from the granularsolidifying units 676 a and 676 b is charged into the sieves 677 a and677 b for sieving. Only ones having a particle diameter under aprescribed level (for example, −6 mm) are transferred through theunder-sieve conveyor 678 and the pneumatic feed pipe 679 to be separator698 b, and after separation from pneumatic air in this separator 698 b,charged into the primary storage silo 680. The granular synthetic resinmaterials having a particle diameter of over the prescribed level aretransferred through the over-sieve conveyor 681 and the pneumatic pipe687 to the separator 682, and after removal from pneumatic air, broughtback to the receiving hopper 671 on the entry side, and charged again,together with the synthetic resins (A), into the granular solidifyingunits 676 a and 676 b.

The synthetic resins (B) are charged, on the other hand, into thereceiving hopper 683 on the entry side of the processing line Y, andthen charged into the primary crusher 685 through the supply conveyor684 for rough crushing (for example, to a particle diameter of about 50mm). Then, the synthetic resins (B) are charged into the secondarycrusher 688 by the transfer conveyor 686 for secondary crushing (forexample, to a particle diameter of about 20 mm). Scrap mixed in thesynthetic resins (B) subjected to primary crushing is removed by themagnetic separator 674 in the middle of the above transfer conveyor 686.

The secondary-crushed synthetic resins (B) are charged by the transferconveyor 689 into the wind selector 690, where foreign matters such asearth, sand and metals are separated and removed by wind selection. Thesynthetic resins (B) after this selection are pneumatically sent throughthe pneumatic feed pipe 691 to the separator 692, where the resins areseparated from pneumatic air, then charged into the cushion tanks 695 ato 695 c through the distributing conveyors 693 and 694, and then sentto the individual milling units 696 a to 696 c (tertiary crushers) formilling to a particle diameter under a prescribed level (for example, to−6 mm), thereby obtaining the granular synthetic resin material (b).This granular synthetic resin material (b) is sent through the pneumaticfeed pipes 697 a to 697 c to the separators 698 a to 698 c forseparation from pneumatic air, and then charged into the primary storagesilo 680.

Pneumatic air separated in the separators 692 and 698 a to 698 c is sentthrough the pipings 699 and 699 a to 699 c to the dust collector 700 forcollection of synthetic resin dust, and the collected synthetic resindust is charged by the under-collector conveyor 701 into the primarystorage silo 680.

The mixture of the granular synthetic resin materials (a) and (b) storedin the primary storage silo 680 is supplied by the constant-volumecutter 704 and the transfer conveyor 702 through the service tank 619 tothe lift tank 621, and pneumatically sent from this lift tank 621 to theblowing station Z. The subsequent steps are the same as those describedas to the construction shown in FIG. 26.

In the apparatus shown in FIG. 39, the mixture of the granular syntheticresin materials (a) and (b) stored in the primary storage silo 680 issupplied by the constant-volume cutter 704 and the transfer conveyor 702to the secondary selector 706 for separation and removal of foreignmatters by wind selection, pneumatically sent through the pneumatic feedpipe 707 to the separator 708 for separation from pneumatic air,supplied through the transfer conveyor 709 and the service tank 619 tothe lift tank 621, and pneumatically sent from this lift tank 621 to theblowing station Z.

Operational Example 1

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 2.5 tons/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 5 tons/hrwere supplied to a processing/blowing apparatus of synthetic resins asshown in FIG. 26 to process the same into a granular synthetic resinmaterials (a) and (b), which were then pneumatically supplied to thetuyere portion of a blast furnace, and were blown, together with grainedcoal, through the tuyere portion into the furnace. Conditions forprocessing and supply of the synthetic resins and operating conditionsof the blast furnace are as follows.

(a) Processing Conditions of Synthetic Resins

(a-1) Synthetic Resins (A)

After rough crushing, synthetic resins were processed through acontraction/solidification/granulation treatment by the following method(3) into a granular synthetic resin material (a) having a particlediameter of under 6 mm, and the same was transferred to the primarystorage silo.

(a- 2) Synthetic Resins (B)

After primary crushing, synthetic resins were processed throughsecondary crushing and milling into a granular synthetic resin material(b) having a particles diameter of under 6 mm, and the same wastransferred to the primary storage silo.

(b) Pneumatic Feed Conditions of Granular Synthetic Resin Material

The mixture of the granular synthetic resin materials (a) and (b)charged into the primary storage silo was cut out in batches of aconstant volume, transferred to the blowing station, pneumaticallysupplied to the tuyere portion of a blast furnace from the blowingstation under the following conditions, and blown into the furnace.

Pneumatic gas: air

Blowing flow rate of pneumatic gas: 1,300 Nm³/hr

Amount of blown granular synthetic resin material: 7.5 tons/hr

Solid/gas ratio: 4.5 kg/kg

(c) Blast Furnace Operating Conditions

Iron production: 9,000 tons/day

Coke rate: 447 kg/t·pig

Tuyere: Amount of blown granular synthetic resin material: 20 kg/t·pig

Amount of blown grained coal: 100 kg/t·pig

Blast volume: 7,260 Nm³/min

Oxygen enrichment ratio: 4%

Blast temperature: 1,000° C.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

Operational Example 2

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 2.8 kg/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 5.6 kg/hrwere supplied to a processing/blowing experimental apparatus ofsynthetic resins as shown in FIG. 27 to process the same into a granularsynthetic resin materials (a) and (b), which were then pneumaticallysupplied to the tuyere portion of an experimental blast furnace, andwere blown, together with grained coal, through the tuyere portion intothe furnace. Conditions for processing and pneumatic supply of thesynthetic resins and operating conditions of the blast furnace were thesame as in the Operational Example 1.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

In this Operational Example, polyvinyl chloride materials accounted forabout 3% of the synthetic resins supplied to the processing lines X andY, and about 99% of these polyvinyl chloride could be separated andrecovered in the separator. Top gas was sampled throughout the entireperiod of operation for analysis of the chemical composition of the gas:almost no HCl was detected.

Operational Examples 3-6

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 2.5 tons/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 5.0 tons/hrwere supplied to a processing/blowing apparatus of synthetic resinsshown in the flowchart of FIG. 26 under the conditions for theOperational Examples 3 to 6 shown in Table 19 to process the same intogranular synthetic resin materials (a) and (b). As shown in Table 19,the processed synthetic resin materials contained, in addition tothermoplastic resins such as polyethylene and polypropylene,polyethylene terephthalate (PET), ABS resin, and polyvinyl chloride(PVC), and contained other resins including thermosetting resins such asurethane resin and phenol resin, plasticizers such as diethylphthalate,hard flammable agents such as trimethyl phosphate and 2.3-dibromopropyl,resins added with glass fiber, calcium carbonate, alumina and clay, andvarious other additives. Earth and sand adhering to the synthetic resinswere also contained (this is also the case with the Operational Examples7 to 16 described later). The processing conditions of synthetic resinswere the same as those in the Operational Example 1.

After processing, the resultant granular synthetic resin materials (a)and (b) were mixed in the primary storage silo, then pneumaticallysupplied to the tuyere portion of a blast furnace from the blowingstation, and blown into the furnace through a blowing lance (25 mm dia.)for waste plastics. Pneumatic feed conditions of the granular syntheticresin materials were as follows. Operating conditions of the blastfurnace are shown in Table 20.

Pneumatic gas: air

Flow rate of blown pneumatic gas: 650 to 2,600 Nm³/hr

Amount of blown granular synthetic resin materials: 3.75 to 15.0 tons/hr

Solid/gas ratio: 4.5 kg/kg

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

Operational Example 7

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 1.5 tons/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 6.6 tons/hrwere supplied to a processing/blowing apparatus of synthetic resinsshown in the flowchart of FIG. 26 under the conditions shown in Table 21to process the same into granular synthetic resin materials (a) and (b).After mixing in the primary storage silo, these granular synthetic resinmaterials (a) and (b) were pneumatically sent from the blowing stationto the blast furnace and blown into the furnace (flow rate of blownpneumatic gas: 1,300 Nm³/hr). Processing conditions of synthetic resinswere the same as those of the Operational Example 1, and pneumatic feedconditions of the processed granular synthetic resin materials were thesame as those of the Operational Examples 3 to 6. Operating conditionsof the blast furnace are shown in Table 22.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

Operational Example 8

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 3.0 tons/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 4.5 tons/hrwere supplied to a processing/blowing apparatus of synthetic resinsshown in the flowchart of FIG. 26 under the conditions shown in Table 21to process the same into granular synthetic resin materials (a) and (b).After mixing in the primary storage silo, these granular synthetic resinmaterials (a) and (b) were pneumatically sent from the blowing stationto the blast furnace and blown into the furnace (flow rate of blownpneumatic gas: 1,300 Nm³/hr). Processing conditions of synthetic resinswere the same as those of the Operational Example 1, and pneumatic feedconditions of the processed granular synthetic resin materials were thesame as those of the Operational Examples 3 to 6. Operating conditionsof the blast furnace are shown in Table 22.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

Operational Example 9

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 5.0 tons/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 2.5 tons/hrwere supplied to a processing/blowing apparatus of synthetic resinsshown in the flowchart of FIG. 26 under the conditions shown in Table 21to process the same into granular synthetic resin materials (a) and (b).After mixing in the primary storage silo, these granular synthetic resinmaterials (a) and (b) were pneumatically sent from the blowing stationto the blast furnace and blown into the furnace (flow rate of blownpneumatic gas: 1,300 Nm³/hr). Processing conditions of synthetic resinswere the same as those of Operational Example 1, and pneumatic feedconditions of the processed granular synthetic resin materials were thesame as those of the Operational Examples 3 to 6. Operating conditionsof the blast furnace are shown in Table 22.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

Operational Example 10

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 1.50 tons/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 2.25 tons/hrwere supplied to a processing/blowing apparatus of synthetic resinsshown in the flowchart of FIG. 26 under the conditions shown in Table 23to process the same into granular synthetic resin materials (a) and (b).After mixing in the primary storage silo, these granular synthetic resinmaterials (a) and (b) were pneumatically sent from the blowing stationto the blast furnace and blown into the furnace (flow rate of blownpneumatic gas: 1,300 Nm³/hr). Processing conditions of synthetic resinswere the same as those of Operational Example 1, and pneumatic feedconditions of the processed granular synthetic resin materials were thesame as those of the Operational Examples 3 to 6. Operating conditionsof the blast furnace are shown in Table 24.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

Operational Example 11

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 4.50 tons/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 6.75 tons/hrwere supplied to a processing/blowing apparatus of synthetic resinsshown in the flowchart of FIG. 26 under the conditions shown in Table 23to process the same into granular synthetic resin materials (a) and (b).After mixing in the primary storage silo, these granular synthetic resinmaterials (a) and (b) were pneumatically sent from the flowing stationto the blast furnace and blown into the furnace (flow rate of blownpneumatic gas: 1,930 Nm³/hr). Processing conditions of synthetic resinswere the same as those of Operational Example 1, and pneumatic feedconditions of the processed granular synthetic resin materials were thesame as those of the Operational Examples 3 to 6. Operating conditionsof the blast furnace are shown in Table 24.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

Operational Example 12

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 5.5 tons/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 9.5 tons/hrwere supplied to a processing/blowing apparatus of synthetic resinsshown in the flowchart of FIG. 26 under the conditions shown in Table 23to process the same into granular synthetic resin materials (a) and (b).After mixing in the primary storage silo, these granular synthetic resinmaterials (a) and (b) were pneumatically sent from the blowing stationto the blast furnace and blower into the furnace (flow rate of blownpneumatic gas: 2,600 Nm³/hr). Processing conditions of synthetic resinswere the same as those of Operational Example 1, and pneumatic feedconditions of the processed granular synthetic resin materials were thesame as those in the Operational Examples 3 to 6. Operating conditionsof the blast furnace as shown in Table 24.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

TABLE 19 OPERATIONAL OPERATIONAL OPERATIONAL OPERATIONAL EXAMPLE 3EXAMPLE 4 EXAMPLE 5 EXAMPLE 6 FILM- LUMPY FILM- LUMPY FILM- LUMPY FILM-LUMPY SHAPED *1 *2 SHAPED *1 *2 SHAPED *1 *2 SHAPED *1 *2 Properties (%)Polyethylene 71.00  92.00  76.00  53.50  65.00  29.00  51.00  33.00 Polypropylene 24.00  4.50 11.00  26.00  28.00  28.00  32.00  23.00 Polystyrene 5.00 0.50 7.00 13.00  3.00 31.50  11.00  23.00  PET 0.000.00 2.00 2.00 3.00 1.50 0.00 1.50 ABS 0.00 0.00 1.00 1.00 0.00 0.000.00 1.50 PVC 0.00 0.00 3.00 0.00 0.00 1.50 1.00 2.50 Other resins 0.000.00 0.00 0.00 1.00 4.00 2.00 9.50 Inorganic 0.00 3.00 0.00 4.50 0.004.50 3.00 6.00 Heat value of 10697 10215 9924 9565 synthetic resinmaterial charged into furnace (kcal/kg) *1: Synthetic resins mainlycomprising film-shaped synthetic resins supplied (A) *2: Syntheticresins mainly comprising lumpy synthetic resins supplied (B)

TABLE 20 Operational Operational Operational Operational ex. 3 ex. 4 ex.5 ex. 6 Iron production (t/day) 9000 9000 9000 9000 Blast temp. (° C.)1000 1000 1000 1000 Blast volume (Nm³/t.pig) 1075 1075 1075 1074 Cokerate (kg/t.pig)  395  396  396  399 Grained coal ratio (kg/t.pig)  100 100  100  100 Synthetic resin ratio (kg/t.pig)  20  20  20  20

TABLE 21 OPERATIONAL OPERATIONAL OPERATIONAL EXAMPLE 7 EXAMPLE 8 EXAMPLE9 FILM- LUMPY FILM- LUMPY FILM- LUMPY SHAPED *1 *2 SHAPED *1 *2 SHAPED*1 *2 Properties (%) Polyethylene 71.00  71.00  66.50  45.67  47.00 48.50  Polypropylene 24.00  14.00  13.00  29.67  28.00  23.50 Polystyrene 5.00 5.00 8.00 13.00  18.00  16.50  PET 0.00 0.00 2.00 3.673.00 1.50 ABS 0.00 0.00 1.00 1.00 0.00 0.00 PVC 0.00 2.50 2.50 0.00 1.002.50 Other resins 0.00 2.50 5.00 3.33 3.00 3.00 Inorganic 0.00 5.00 2.003.67 0.00 4.50 Heat value of synthetic 10194 9990 9941 resin materialcharged into furnace (kcal/kg) *1: Synthetic resins mainly comprisingfilm-shaped synthetic resins supplied (A) *2: Synthetic resins mainlycomprising lumpy synthetic resins supplied (B)

TABLE 22 Operational Operational Operational ex. 7 ex. 8 ex. 9 Ironproduction (t/day) 9000  9000  9000  Blast temp. (° C.) 950 950 925Blast volume (Nm³/t.pig) 1104  1104  1120  Coke rate (kg/t.pig) 403 405409 Grained coal ratio (kg/t.pig) 100 100 100 Synthetic resin ratio(kg/t.pig)  20  20  20

TABLE 23 OPERATIONAL OPERATIONAL OPERATIONAL EXAMPLE 10 EXAMPLE 11EXAMPLE 12 FILM- LUMPY FILM- LUMPY FILM- LUMPY SHAPED *1 *2 SHAPED *1 *2SHAPED *1 *2 Properties (%) Polyethylene 66.00  71.00  62.00  43.67 41.50  45.45  Polypropylene 24.00  14.00  13.00  26.33  26.50  19.39 Polystyrene 8.00 4.67 8.00 13.00  18.00  16.42  PET 0.00 0.00 4.20 2.203.60 4.23 ABS 0.00 0.00 1.00 1.00 0.00 3.16 PVC 1.00 1.00 2.50 3.33 2.501.71 Other resins 1.00 2.67 7.30 5.13 6.40 1.03 Inorganic 0.00 6.67 2.005.33 1.50 8.61 Heat value of synthetic 10238 9674 9480 resin materialcharged into furnace (kcal/kg) *1: Synthetic resins mainly comprisingfilm-shaped synthetic resins supplied (A) *2: Synthetic resins mainlycomprising lumpy synthetic resins supplied (B)

TABLE 24 Operational Operational Operational ex. 10 ex. 11 ex. 12 Ironproduction (t/day) 9000 9000 9000 Blast temp. (° C.) 1000 1000 1000Blast volume (Nm³/t.pig) 1071 1077 1080 Coke rate (kg/t.pig)  408  388 378 Grained coal ratio (kg/t.pig)  100  100  100 Synthetic resin ratio(kg/t.pig)  10  30  40

Operational Examples 13 to 16

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials and synthetic resins (B) mainly comprising lumpy syntheticresin materials were supplied to a processing/blowing apparatus ofsynthetic resins shown in the flowchart of FIG. 27 under the conditionsshown in Tables 25 and 26 for the Operational Examples 13 to 16 toprocess the same into granular synthetic resin materials (a) and (b).

After mixing in the primary storage silo, these processed granularsynthetic resin materials (a) and (b) were pneumatically sent from theflowing station to the blast furnace, and blown into the furnace througha waste plastic blowing lance (25 mm dia.). Processing conditions ofsynthetic resins were the same as those of Operational Example 1, andpneumatic feed conditions of the processed granular synthetic resinmaterials were the same as those of the Operational Examples 3 to 6. Forthe individual Operational Examples 13 to 16, the amount of processedand furnace-supplied synthetic resins, and properties thereof are shownin Tables 25 and 26, and operating conditions of the blast furnace areshown in Table 27.

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the blastfurnace operation itself showed no trouble, and there occurred almost nosupply trouble such as clogging of the cutting portion of the storagesilo or in the pneumatic feed pipe system of the granular syntheticresin materials.

Top gas was sampled throughout the entire period of operation foranalysis of the chemical composition of the gas: almost no HCl wasdetected.

TABLE 25 OPERATIONAL EXAMPLE 13 OPERATIONAL EXAMPLE 14 Suppliedsynthetic resins Supplied synthetic resins FILM- LUMPY Total after FILM-LUMPY Total after SHAPED *1 *2 treatment SHAPED *1 *2 treatment Quantitysupplied (t/hr) 2.89 5.57 7.50 3.21 5.21 7.50 Properties (%)Polyethylene 71.00  66.00  75.86  51.00  46.20  53.52  Polypropylene11.00  14.00  14.45  27.50  29.50  32.12  Polystyrene 2.00 4.00 3.592.00 6.80 5.47 PET 0.00 0.00 0.00 1.50 1.00 1.34 ABS 0.00 0.00 0.00 2.000.00 0.86 PVC 11.00  11.00  1.04 8.60 11.50  0.95 Other resins 0.00 2.001.49 2.40 2.00 2.42 Inorganic 5.00 3.00 3.57 5.00 3.00 3.43 Heat valueof synthetic resin material 10354 10146 charged into furnace (kcal/kg)*1 Synthetic resins mainly comprising film-shaped synthetic resin (A) *2Synthetic resins mainly comprising lumpy synthetic resin (B)

TABLE 26 OPERATIONAL EXAMPLE 15 OPERATIONAL EXAMPLE 16 Suppliedsynthetic resins Total after Supplied synthetic resins Total afterFILM-SHAPED *1 LUMPY *2 treatment FILM-SHAPED *1 LUMPY *2 treatmentQuantity supplied (t/hr) 3.15 5.21 7.49 4.20 4.70 7.50 Properties (%)Polyethylene 43.20  41.30  46.47  39.50  33.00  42.06  Polypropylene23.40  27.60  28.87  22.40  28.50  30.07  Polystyrene 9.50 11.20  11.67 9.10 11.20  11.83  PET 1.50 1.00 1.33 1.50 1.00 1.47 ABS 3.40 0.00 1.393.40 1.20 2.34 PVC 8.60 9.80 0.77 12.40  14.80  1.20 Other resins 4.806.10 5.98 6.10 7.30 7.55 Inorganic 5.60 3.00 3.52 5.60 3.00 3.47 Heatvalue of synthetic resin material 9915 9795 charged into furnace(kcal/kg) *1 Synthetic resins mainly comprising film-shaped syntheticresin (A) *2 Synthetic resins mainly comprising lumpy synthetic resin(B)

TABLE 27 Operational Operational Operational Operational ex. 13 ex. 14ex. 15 ex. 16 Iron production (t/day) 9000 9000 9000 9000 Blast temp. (°C.) 1000 1000 1000 1000 Blast volume (Nm³/t.pig) 1074 1076 1077 1077Coke rate (kg/t.pig)  395  395  396  398 Grained coal ratio (kg/t.pig) 100  100  100  100 Synthetic resin ratio (kg/t.pig)  20  20  20  20

Operational Example 17

Synthetic resins (A) mainly comprising film-shaped synthetic resinmaterials in an amount of 14.6 kg/hr and synthetic resins (B) mainlycomprising lumpy synthetic resin materials in an amount of 29.2 kg/hrwere supplied to a processing/blowing apparatus of synthetic resinsshown in the flowchart of FIG. 26 to process the same into granularsynthetic resin materials (a) and (b). After mixing in the primarystorage silo, these granular synthetic resin materials (a) and (b) werepneumatically sent from the blowing station to a scrap meltingexperimental furnace (shaft furnace) and blown, together with grainedcoal through tuyeres into the furnace. In this Operational Example, ascrap melting experimental furnace (inner volume: 2.5 m³, ironproduction: 10 tons/day) having burners at a plurality of tuyeres of thefurnace body was used. Grained coal PC and granular synthetic resinmaterial SR were blown from a solid fuel blowing port and at the burnerradial center or in the proximity thereof from the combustion burners ofthe tuyeres, and oxygen at the room temperature was blown from an oxygenblowing port b therearound. Simultaneously, steam was blown as a coolantfor adjusting temperature.

Processing and supply conditions of synthetic resins and operatingconditions of the scrap melting experimental furnace are shown below.

(a) Processing conditions of synthetic resins

Same as in the Operational Example 1.

(b) Pneumatic feed conditions of granular synthetic resin material

The mixture of granular synthetic resin materials (a) and (b) charged inthe primary storage silo is cut out from the silo in batches of aconstant volume, transferred to the blowing station. The granularsynthetic resin materials were pneumatically sent from the blowingstation to tuyeres of a blast furnace under the following conditions andblown into the furnace.

Pneumatic gas: air

Flow rate of blown pneumatic gas: 7.6 Nm³/hr

Amount of blown granular synthetic resin material: 43.8 kg/hr

Solid/gas ratio: 4.5 kg/kg

(c) Operating conditions of scrap melting experimental furnace

Iron production: 10 tons/day

Coke rate: 265 kg/t·pig

Converter slag ratio: 121 kg/t·pig

Silica ratio: 5 kg/t·pig

Tuyere: Amount of blown granular synthetic resin material: 105 kg/t·pig

Amount of blown grained coal: 175 kg/t·pig

Amount of blast oxygen: 206 Nm³/t·pig

Amount of steam: 7 Nm³/t·pig

Blowing of the above-mentioned granular synthetic resin materials intothe furnace was carried out for seven days. As a result, the scrapmelting experimental furnace operation itself showed no trouble, andthere occurred almost no supply trouble such as clogging of the cuttingportion of the storage silo or in the pneumatic feed pipe system of thegranular synthetic resin materials.

In this Operational Example, polyvinyl chloride materials accounted forabout 3% of the synthetic resins supplied to the processing lines X andY, and about 99% of these polyvinyl chloride could be separated andrecovered in the separator. Top gas was sampled throughout the entireperiod of operation for analysis of the chemical composition of the gas:almost no HCl was detected.

Operational Example 18

Magnetic cards and the like rejected as defective products or waste(including combination cards such as cards using paper, and cardsincorporating ICs as storage medium) were supplied to aprocessing/blowing apparatus of synthetic resins shown in the flowchartof FIG. 26, then after processing, pneumatically fed to a blast furnaceand blown into the furnace.

Magnetic cards, which are used for diverse and various purposes, arebroadly divided into the following two kinds in terms of thickness:

(1) Thickness of at least 0.5 mm: cash card, various identificationcards;

(2) Thickness under 0.5 mm: telephone card, ticket, various prepaidcards.

Results of investigation through previous tests suggest that, for theforegoing magnetic cards, cards having a thickness of under 0.5 mm, ifsimply crushed, form scaly flakes. When applied with pressure in a tankof the pneumatic feed system, flakes adhere with each other, eliminatingvoids. This leads to loss of slip between crushed pieces and ofaeration, resulting in easy occurrence of supply any problems such asscaffolding. In this Operational Example, therefore, cards of (2) abovehaving a thickness of under 0.5 mm were classified as synthetic resins(A) mainly comprising film-shaped synthetic resin materials, and cardsof (2) above having a thickness of at least 0.5 mm were classified assynthetic resins (B) mainly comprising lumpy synthetic resin materials.These cards were processed in a processing/blowing apparatus ofsynthetic resins shown in the flowchart of FIG. 26 into granularsynthetic resin materials (a) and (b).

After processing, the granular synthetic resin materials (a) and (b)were mixed in the primary storage silo, and pneumatically supplied fromthe blowing station to the blast furnace, and blown into the furnacethrough a waste plastics blowing lance (25 mm dia.).

Processing and pneumatic feed conditions of synthetic resins and blastfurnace operating conditions were as follows.

(a) Processing conditions of synthetic resins

Same as in the Operational Example 1.

(b) Pneumatic feed conditions of granular synthetic resin material

The mixture of the granular synthetic resin materials (a) and (b)charged into the primary storage silo were cut out from the silo inbatches of a constant volume, transferred to the blowing station.Granular synthetic resin materials were pneumatically sent to thetuyeres of the blast furnace from the blowing station under thefollowing conditions, and blown into the furnace. Pneumatic gas: air

Amount of blown pneumatic gas: 1,200 Nm³/hr

Amount of blown granular synthetic resin material: 62.5 kg/min Solid/gasratio: 2.4 kg/kg

(c) Operating conditions of blast furnace

Iron production: 9,000 tons/day

Blast volume: 7,260 Nm³/min

Oxygen enrichment ratio: 4%

Blast temperature: 1,200° C.

Coke rate: 447 kg/t·pig

Amount of blown grained coal: 100 kg/t·pig

Amount of blown granular synthetic resin material: 10 kg/t·pig

Blowing of these granular synthetic resin materials was carried out fortwo days. As a result, the blast furnace operation itself showed notrouble, and there occurred almost no supply trouble such as clogging ofthe cutting portion of the storage silo or in the pneumatic feed pipesystem of the granular synthetic resin materials.

Operational Example 19

Only polyethylene terephthalate resin (PET) bottles were selected fromamong plastic bottles collected as waste, which were processed underconditions (a) and (b) below, pneumatically sent to the blast furnace,and blown into the furnace. Selection of PET bottles were conducted bymeans of a material determination unit (made by Toa Denpa Kogyo Co.,Ltd.) or by manual operation.

In the Operational Example (a), PET bottles were supplied only to theprocessing line Y of the processing/blowing apparatus of syntheticresins shown in the flowchart of FIG. 26, totally crushed in the formwith caps and labels attached thereon to a particle diameter under 6 mm(however, metal caps were removed after crushing), pneumatically sent tothe blast furnace, and blown into the furnace.

In the Operational Example (b), PET bottles were supplied only to theprocessing line X of the processing/blowing apparatus of syntheticresins shown in the flowchart of FIG. 26, processed with caps and labelsattached thereto into a granular synthetic resin material having aparticle diameter of under 6 mm (however, metal caps were removed aftercrushing), pneumatically supplied to the blast furnace, and blown intothe furnace.

Processing and pneumatic feed conditions of synthetic resins and blastfurnace operating conditions in the Operational Examples (a) and (b) areshown below.

(a) Processing conditions of synthetic resins

Operational Example (a): Same as in (a- 2) in the Operational Example 1.

Operational Example (b): Same as in (a- 1) in the Operational Example 1.

In each of the Operational Examples (a) and (b), the granular syntheticresin materials charged in the primary storage silo were cut out inbatches of a constant volume from the silo, transferred to the blowingstation, pneumatically sent from the blowing station under the followingconditions to tuyeres of the blast furnace, and blown into the furnace.

Pneumatic gas: air

Amount of blown pneumatic gas: 1,200 Nm³/hr

Amount of blown granular synthetic resin material: 62.5 kg/min Solid/gasratio: 2.4 kg/kg

(c) Blast furnace operating conditions

Iron production: 9,000 tons/day

Blast volume: 7,260 Nm³/min

Oxygen enrichment ratio: 4%

Blast temperature: 1,200° C.

Coke rate: 447 kg/t·pig

Amount of blown grained coal: 100 kg/t·pig

Amount of blown granular synthetic resin material: 10 kg/t·pig

The foregoing operation was carried out for two days. As a result, inthe Operational Example (a), the amount of the granular synthetic resinmaterial blown into the blast furnace was not stabilized (there werepulses in the amount of blowing), and the blowing stopping time reachedeven 4.6 hr/day in average. As a result of investigation, instability ofthis amount of blowing is caused by a defective cutting of the granularsynthetic resin materials from the tank of the pneumatic feed system.More specifically, crushing chips (scaly flakes) of the granularsynthetic resin material when pressure is applied in the tank of thepneumatic feed system adhere to each other, eliminating voids, slipbetween crushed chips and aeration. This causes scaffolding or othersupply any problems.

In the Operational Example (b), on the other hand, there occurred nosupply trouble of the granular synthetic resin materials as in theOperational Example (a), and no hindrance in the blast furnace operationitself.

According to the blowing apparatus of synthetic resin materials of thepresent invention, as described above, synthetic resins such as plasticscan be provided as a fuel or an iron reducing agent to be blown into ablast furnace or a scrap melting furnace, irrespective of the formthereof. This permits quantity treatment and effective use of wastesynthetic resins, and further, considerable reduction of the fuel costin a blast furnace or the like. It is also possible to effectivelyimprove fluidity, transferability and combustion property of syntheticresins supplied to a furnace, and to appropriately supply syntheticresins as a fuel or an iron reducing agent into the furnace withoutcausing any trouble in the furnace operation. A problem caused bychlorine-containing macromolecular resins such as polyvinyl chloridecontained in synthetic resins is never posed, and synthetic resins canbe supplied as a fuel or an iron reducing agent to be blown into a blastfurnace.

Embodiment 8

To solve the foregoing problems, the present inventors have madeintensive research and gained those findings which will follow.

First of all, upon inspection of the combustion zone out of a peep holefor the tuyere, coal blown into the furnace via the tuyere, i.e., finelygrained coal, has been found to immediately thermally decompose with theescape of its volatile components so that the coal gets minutely sized,eventually flying out of the combustion zone. By contrast with the coal,a synthetic resin material of a large particle diameter is retained in acombustively swirling manner in the combustion zone for an extendedperiod of time, and this swirling retention continues until the particlesize becomes fine to some extent. It is required that, in order toattain enhanced combustion ratio, the synthetic resin material bebrought into completely combustive condition in shortened time while itis being retained as stated above. To this end, it has been found thatthe synthetic resin material needs to have a proper specific surfacearea as described hereunder.

As mentioned above, when blown into the furnace out of the tuyere, thesynthetic resin material and coal show their respective differentbehaviors in the combustion zone. With regard to a synthetic resinmaterial to be blown into the blast furnace, it has been found that thecombustion ratio can be improved by setting the specific surface area ina certain appropriate range since such resin material has conditionsadapted to be easily retentive in the combustion zone.

The present invention, which has been completed based on theaforementioned findings, is concerned with a method of the production ofa pig iron by blowing a synthetic resin material into a vertical furnaceout of a tuyere thereof, characterized in that such resin material hasan average specific surface area of 50 m²/kg or above.

The synthetic resin material for use in the invention may containparticles of smaller than 1 mm in particle diameter in a proportion ofmore than 5% by weight and an average specific surface area of 25 m²/kgor above. Alternatively, the synthetic resin material may have foamedparticles in a proportion of more than 3% by weight and an averagespecific surface area of 20m²/kg or above.

Preferred examples of the present invention will now be described withreference to the drawings.

FIG. 40 is a schematic view explanatory of a certain preferred exampleof the present invention. Iron ore 803, iron sources such as scrap 804and the like and coke 805 are charged from a top 802 of a blast furnace801, while a high-temperature oxygen-rich air 807 and a given syntheticresin material 808 are blown into the furnace out of tuyeres 806 locatedat a bottom of the furnace. The synthetic resin material 808 iseffectively subjected to combustion in combustion zones 809 generatedinternally of the furnace 801 and fowardly of the tuyeres 806. Thesynthetic resin material 808 is blown halfway into an oxygen-rich airfeed conduit 810.

The combustion ratio of a synthetic resin material in a combustion zonecan be enhanced by increasing the resin material in respect of itsaverage specific surface area. Average specific surface areas exceeding50 m²/kg enable the resultant synthetic resin material to afford acombustion ratio at a good level. It is to be noted here that thespecific surface area is variable with the shape of synthetic resinmaterials used. A synthetic resin material, derived for instance fromcontraction and solidification in which a starting synthetic resinmaterial is heated into a semi-molten state and then solidified byquenching, is preferred because it provides an irregular shape havingresin particles aggregated and hence shows a large specific surfacearea. In the case of blowing of such resin material into the combustionzone, a resin portion having a large specific surface area (finelygrained or irregularly shaped resin portion) begins first withcombustion (hereunder called “preceding combustion”), whereas a coarselygrained resin portion undergoes thermal decomposition and then proceedsto combustion. As a result, the synthetic resin material thus blown intothe combustion zone is improved in regard to its combustion ratio on thewhole.

Additionally, a synthetic resin material containing a resin portion ofsmaller than 1 mm in particle diameter is highly effective for precedingcombustion. In this instance, such resin portion needs to be containedin a proportion of more than 5% by weight. To gain improved combustionratio, the whole synthetic resin material may be set at 25 m²/kg orabove in average specific surface area.

More effective preceding combustion and hence enhanced combustion ratioare attainable from mixture of a foam-shaped resin in place of thegranular equivalent. The reason behind this is that the foam-shapedresin is porous on its outer surface. In such case, the foam-shapedresin may be added in a proportion of more than 3% by weight with thewhole synthetic resin material set at 20 m²/kg or above.

Suitable synthetic resin materials may be hydrocarbon compounds of apolymeric class such as polyethylene, polypropylene, polystyrene and soon. No particular restriction is placed on the kind of polymerichydrocarbon compounds.

Further, suitable synthetic resin materials of a foam shape may befoamed products such as of foamed polyethylene, foamed polystyrene andthe like that have been in common use as food packages or as heatinsulators, but the kind of foamed products is not limiting. In the casewhere foam-shaped resin materials are blown into a vertical furnace,they may be used singly or in combination with finely grained coal.

Examples

With reference to the following examples, the present invention will befurther described below in greater detail.

FIG. 41 is a schematic view, taken vertically cross-sectionally, of acombustion testing apparatus equipped with a vertical furnace andemployed for carrying out the method of the present invention where asynthetic resin material is blown into the furnace. The testingapparatus shown here simulates an actual blast furnace with a tuyeredesignated at 806, a combustion zone at 809, a coke-filled layer at 811,a hot air at 812, a synthetic resin material hopper at 813, a cokehopper at 814, a counter rod at 815, a combustion gas at 816 and afurnace body at 817.

In Table 28 are shown major conditions set for combustion testing withuse of the above testing apparatus.

Coke of 20 to 30 mm in particle diameter was supplied from the cokehopper 814 and charged out of a furnace top into the furnace, and thefilling level of coke was adjusted to hold a void at 0.6 by means of thecounter rod 815. On the other hand, a hot air 813 of 1,200° C. was blownin an amount of 350 Nm³/hr into the furnace out of the tuyrere 806,while a synthetic resin material was conveyed from the synthetic resinmaterial hopper 813 and blown into the furnace. The amount of such resinmaterial blown was 30 kg/hr, which amount was equivalent to 90 kg/tonreduced from the blow amount of a fuel (blow ratio of a fuel) requiredfor 1 ton of pig iron to be produced by use of a blast furnace. The flowrate of a gas at a tip of the tuyere 806 was computed to be 145 m/sec.Thus, both the coke present in the coke-filled layer 811 and thesynthetic resin material so blown were made vigorously combustible witheventual generation of a combustion zone 809 at a forward region of thetuyere 806.

Two different synthetic resin materials available usually as wastes wereselectively used. One such waste had a smaller specific surface area(type A), and the other arose from contraction and solidification andhad a larger specific surface area (type B). The specific surface areaswere measured by means of a gas absorption method such as BET or thelike.

With use of the combustion testing apparatus stated above, measurementwas made of the combustion ratios as to synthetic resin materials. Thecombustion ratio α of such a resin material was defined by the followingequation and computed therefrom.

α={(A−C)β/C}×100

where A is the coke consumption (kg/hr) where a synthetic resin materialis not blown in, B is the coke consumption (kg/hr) where a syntheticresin material is blown in, β is the carbon content in coke, and C isthe carbon content in a synthetic resin material blown in (kg/hr).

Tests [1] to [3] indicated below were conducted based upon the abovestated methods.

Test [1]

The combustion ratios of synthetic resin materials were examined withthe specific surface areas varied. The test results are shown in Table29 below.

As evidenced by the results of Table 29, the combustion ratios ofExamples 1 to 4 falling within the scope of the present invention arenoticeably excellent as compared to those of Comparative Examples 1 to 5deviating in scope from the invention.

Test [2]

The combustion ratios of synthetic resin materials were checked withvariations as concerns the particle diameters of fine resin particles,the contents of a portion of such fine resin particles and the averagespecific surface areas of synthetic resin materials in their entirety.The test results are shown in Table 30 below.

The results of Table 30 demonstrate that if even one of the threeparameters named above is outside the scope of the present invention,the resulting synthetic resin material is responsible for decreasedcombustion ratio, say below 75%, and that all such parameters havingsatisfied the scope of the invention lead to a good combustion ratio aslarge as above 88%.

Test [3]

The combustion ratios of synthetic resin materials were checked withvariations as concerns the contents of foam-shaped resin materials andthe average specific surface areas of synthetic resin materials in theirentirety. The test results are listed in Table 31.

The results of Table 31 reveal that a departure of even either one ofthe two parameters from the scope of the present invention invites acombustion ratio as small as below 72% and that both of the parametershaving met with the scope of the invention bring about a combustionratio as large as above 90%.

With the present invention constituted as described hereinabove, asynthetic resin material when used as a heat source for a verticalfurnace in the production of pig iron can be rendered combustively to amarkedly great degree and with savings in coal and coke. Anotheradvantage is that waste synthetic resin materials, wasted heretofore byincineration and reclamation, suit as an auxiliary fuel for use invertical furnaces, contributing eventually to a great solution toenvironmental pollution. Thus, the present invention is industriallysignificant.

TABLE 28 Blast volume (Nm³/hr) 350 Blast temp. (° C.) 1200 Blast gasanalysis (vol. %) O₂ 77 N₂ 23 Tuyere nose gas flow velocity (m/sec) 145Coke particle diameter (mm) 20 to 30 Void ratio upon charging coke (-)0.6 Quantity of blown synthetic resin material (kg/hr) 30 Syntheticresin material analysis (wt. %) C 84 H 14

TABLE 29 Comp. Comp. Comp. Comp. Comp. Example 1 Example 2 Example 3Example 4 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Synthetic Type B B B A = 50 wt.% A A A A A resin B = 50 wt. % material Particle 6 mm 8 mm 10 mm 6 mm 6mm 10 mm 6 to 10 8 to 10 10 to 12 diameter (mm) or loss or less or lessor less or less or less mm mm mm or less or less or less Averagespecific 88.0 67.0 54.0 55.0 20.6 17.7 15.1 11.8  9.5 surface area(m²/kg) Combustion ratio of synthetic 94 91 82 90 70 49 35 26 18 resinmaterial (%)

TABLE 30 Comp. Comp. Comp. Comp. Ex. Example 4 Example 5 Example 6Example 7 Ex. 6 Ex. 7 Ex. 8 9 Synthetic resin Particle diameter 6 mm 8mm 10 mm 10 mm 10 mm 10 mm 10 mm 8 mm material −1 (mm) or less or lessor less or less or less or less or less or less Average specific  32.5 25  17.7  17.7  17.7  17.7 17.7 25 OK? surface area (m²/kg) Proportion(wt. %)  95  95  95  90  97  99 90 70 Synthetic resin Particle diameter1 mm 1 mm 1 mm 1 mm 1 mm 0.5 mm 3 mm 5 mm material −2 (mm) or less orless or less or less or less or less or less or less Average specific212 212 212 212 212 300 90 35 Surface area (m²/kg) Proportion (wt. %)  5 5  5  10  3  1 10 30 Average specific surface area of  42  35  28  38 24  20 25 28 synthetic resin material (m²/kg) Combustion ratio ofsynthetic resin  97  95  88  96  70  54 62 73 material (%)

TABLE 31 Comp. Comp. Example 8 Example 9 Example 10 Example 11 Example12 Ex. 10 Ex. 11 Synthetic Particle diameter (mm) 10 mm 10 mm 8 mm 6 mm10 mm 10 mm 10 mm resin material or less or less or less or less or lessor less or less −1 Average specific surface area  17.7  17.7  25  32.5 17.7  17.7  17.7 (m²/kg) Proportion (wt. %)  90  95  95  95  97  99 99.5 Synthetic Particle diameter (mm) 10 mm 10 mm 10 mm 10 mm 10 mm 10mm 10 mm resin material or less or less or less or less or less or lessor less −2 Average specific surface area 154 154 154 154 154 154 154(m²/kg) Proportion (wt. %)  10  5  5  5  3  1  0.5 Average specificsurface area of synthetic  31  24  33  39  22  19  18 resin material(m²/kg) Combustion ratio of synthetic resin material  94  92  96  97  90 72  56 (%)

Embodiment 9

Continued research have been made by the present inventors so as toeliminate the problems discussed above.

In general, synthetic resins are composed of hydrocarbons and, whenblown into a blast furnace, are completely decomposed into C and H atomsat a region adjacent to a tuyere, which atoms act cooperatively as areducing agent. Consequently, the larger number of C and H atoms perunit blow weight, the synthetic resin material is greater in its heatvalue and more effective as a reducer. Both reducing and heatingcapabilities, therefore, are adjudged in terms of heat value. For thatreason, synthetic resin materials hitherto disposed can be used toadvantage by incorporating a suitable amount of a low-reduction low-heatvalue resin material into a high-reduction high-heat value counterpart.

In order to prepare a composite synthetic resin material flowing fromintermixing a plurality of different resin materials as stated above, itis made necessary that waste synthetic resin materials be first sortedaccording to their qualities and then be determined in regard to theirheat values and that the resin materials be admixed such that the heatvalue of each such resin material is rendered beyond a given level asmeasured by a predetermined equation for proportional intermixing.

The present invention has been completed with the above findings takenin view. In this Embodiment, a method can be effected in which syntheticresin materials are blown into a metallurgical furnace.

In the operation of a metallurgical furnace wherein a plurality of typesof synthetic resin materials are blown out of a tuyere, the qualities ofthose resin materials can be determined by a given determination method,and their heat values are determined from the results of such qualitydetermination when the resin materials are observed free from impuritiessuch as paper, fabric, metal and so on. In the case of inclusion ofthose impurities, the heat values are actually measured by suchdetermination method. If the qualities are not determinable by the abovegiven determination method, then the heat values are subject to actualmeasurement with use of such determination method. Subsequently, two ormore synthetic resin materials are intermixed according to the heatvalue of each such resin material, which heat value is determinable bythe foregoing method in which a mixture of two or more different typesof synthetic resin materials shows a given heat value. The resinmaterials thus mixed are blown into the furnace out of the tuyere.

A preferred form in which the present invention is implemented will befurther described with reference to the drawings.

FIG. 42 is a flow diagram showing the relationship between the qualitydetermination and the heat value determination concerning syntheticresin materials to be blown into a metallurgical furnace in the practiceof the present invention. Waste synthetic resin materials are sortedinto ones composed predominantly of film-like resins (hereunder called“film-shaped synthetic resin material”) and ones composed mainly ofplate-like, bolt-like and other molded forms (hereunder called “solidsynthetic resin materials”), followed by analysis of the sorted resinmaterials on a quality determining apparatus. Synthetic resin materialsdetermined at A1 to be certain of their qualities are passed on to A2 toinspect impurities held in meshed, bonded or otherwise attachedcondition, such as paper, fabric and/or metal. A synthetic resinmaterial found free of impurities is determined in its heat value fromamong those heat values previously known with respect to the qualitiesas determined.

Even if its quality can be determined, a synthetic resin material whenfound involved in impurities at a stage of A2 is actually measured inregard to its heat value by a given method at a stage of A4 anddetermined as such. This is because the impurities produce a decline inheat value. A synthetic resin material when found undeterminable of itsquality for some reasons at a stage of A1 are also measure data A4 fordetermination of its heat value. The method of measuring the heat valuesof synthetic resin materials may be effected as stipulated for exampleby JIS M8814.

The synthetic resin materials having their respective heat valuesdetermined through the above noted methods include such having a lowerheat value than coke. One important feature of the present inventionlies in making it possible to effectively utilize those resin materialswhich, owing to the lower heat values than coke, have not heretoforebeen used for blowing into a blast furnace or a metallurgical furnace.In this case, the resin materials of a lower heat value are mixed in anappropriate proportion with those resin materials having a higher heatvalue than coke and having been blown into the furnace with the resultthat the resulting composite resin material shows a given heat value.This intermixing is so made as to satisfy the following equations (11)and (12).

(aα+bβ+cγ+. . . )/100≧Q  (11)

α+βγ+. . . =100  (12)

where a, b, c, . . . are the heat values of synthetic resin materials ofqualities A, B, C, . . . (kcal/kg), α, β, γ, . . . are the the mixingproportions of synthetic resin materials of qualities A, B, C, . . . (%by weight), and Q is the heat value of coke recognized typical for usein practical operation.

Next, the process stage where the qualities of synthetic resin materialsare determined in the associated production line should be chosen at alocation in which the resin materials are sorted according to thequalities determined are conveniently controlled in their cut amounts ata predetermined process stage between the receipt of waste syntheticresin materials and the blowing of the same into a blast furnace or ametallurgical furnace. The best possible location, therefore, should bedecided with particular regard to the kind of and the sequence ofapparatus to be installed between the apparatus for receiving wastesynthetic resin materials and the apparatus for blowing the same intothe furnace.

FIG. 43 illustrates an example of an equipment layout for blowingsynthetic resin materials into a metallurgical furnace in the practiceof the present invention. Film-shaped and solid synthetic resinmaterials after being received are pretreated and mixed with those resinmaterials of different qualities in a predetermined proportion so that acomposite synthetic resin material is prepared to have a heat valuesuitable for blowing into a blast furnace or a metallurgical furnace.

A film-shaped synthetic resin 901 a transferred from a stock yard (notshown), is cut to a given shape into pseudo-bonded form due tofrictional heat exerted by cutting, whereby film-shaped resin pieces areprepared in superposed relation to each other and then separated fromeach other by use of a separator 904. The film-shaped resin pieces soseparated are treated with a magnetic selector 905 to thereby removeiron dust and so on and thereafter passed through a quality determiningapparatus 902 a so as to determine the kind of such resin pieces.

The quality determining apparatus 902 a is provided with a qualitydetector and a feeding conveyor. A probe attached to the detectortravels, for a given time, in synchronism with the film-shaped resinpieces being continuously transported at a given speed on the conveyor,thereby analyzing the qualities of such resin pieces situated at a spotregion of the probe on the conveyor. Thereafter, the resin pieces aredetermined in respect of their heat values from the results of qualitydetermination thereof (see FIG. 42), followed by charging of the resinpieces in a melting/solidifying/granulating apparatus 909 and bysubsequent treatment of the same as previously determined.

The synthetic resin material 901 a′ granulated by means of themelting/solidifying/granulating apparatus 909 is allowed to pass througha sieve and a separator 910, and those resin portions having a smallerparticle diameter than the predetermined level are successively storedin heat value-sorted hoppers 906 a, 906 b, 906 c, . . . Here, the heatvalues of the granular synthetic resins stored in those hoppers areassumed to be p₁, p₂, p₃, . . . (kcal/kg). Those resin portions having ahigher particle diameter than the predetermined level are classifiedinto large-grained resins and small-grained resins. The large-grainedresins are again put into the cutting apparatus 903, whereas thesmall-grained resins are fed together with coke into the furnace 934 outof a furnace top 934′, or put outside the system of this Embodiment forcharge in a coke furnace, for charge in a sintering furnace or forintermixing with lime.

The granular synthetic resin material 901 a′ stored in the heatvalue-sorted hopper 906 is mixed, in a subsequent process stage, with agiven proportion of a crushed resin material derived from predeterminedtreatment of the solid resin material 901 b and stored in a crushedsynthetic resin material tank 929.

On the other hand, the solid resin material 901 b is crushed coarsely bya primary crusher 920 and treated with use of a primary magneticselector 921 to thereby remove iron dust and the like, followed byfinely crushing of the coarse resins with a secondary crusher 922 and bysubsequent treatment of the fine resins with a secondary magneticselector 923 so as to remove iron dust and other foreign matter. Thesynthetic resins pseudo-bonded through frictional heat generated bycrushing are separated by means of a separator 924 into separatedcrushed synthetic resins material 901 b′ which are then analyzed as totheir qualities by passage through the quality determining apparatus 902b. Like the first-mentioned determining apparatus 902 a, the qualitydetermining apparatus 902 b is provided with a quality detector and afeeding conveyor. A probe attached to the detector travels, for a giventime, in synchronism with the crushed resins being continuouslytransported at a given speed on the conveyor, thereby analyzing thequalities of such crushed resins situated on the conveyor. Thedetermining apparatus 902 a may also be used here, where desired, inplace of the last-mentioned determining apparatus 902 b.

Subsequently, the heat values of the cut synthetic resins are determinedby the above stated method as the result of quality determination (seeFIG. 42). The resin cuts are stored in heat value-sorted hoppers 925 a,925 b, 925 c, . . . Of the cut synthetic resins stored in these hoppers,those cuts of larger and smaller heat values than the predeterminedlevel are taken out and admixed together in a mixing apparatus 926 inthe following way.

To obtain the heat value n (kcal/kg) of a mixture of resin cuts n(kcal/kg), the heat values thereof q₁, q₂, q₃, . . . (kcal/kg) and themixing proportions thereof β₁, β₂, β₃, . . . (% by weight) should be setto meet with the following equations (13) and (14) and besides should bebased on the balance expected from the storage volume and target demandof each of the cut synthetic resins and on the heat volumes of thelatter. This is performed by means of a control counter 926 a.

(q ₁ β ₁ +q ₂ β ₂ +q ₃β₃. . . )/100=n  (13)

β₁+β₂+β₃+. . . =100  (14)

where n is, for example, a constant heat value above 7,500 kcal/kg ofcoke. A cutting valve 926 b works upon receipt of signals coming out ofthe counter 926 a, automatically cutting the cut resins into a mixer 927that mixes the same, and the resulting mixture passes through a sieveand a separator 928. Those resins having a cut diameter up to thepredetermined level are stored in a cut resin storage tank 929, whereasthose resins having a cut diameter larger than the predetermined level,like the granular resins mentioned above, are classified into large cutsand small cuts. The large resin cuts are returned back to the cuttingapparatus 903, and the small resin cuts are fed together with coke outof the furnace top 934′, or put outside the system of this Embodimentfor charge in a coke furnace, for charge in a sintering furnace or formixing with lime.

In such way, in the hoppers 906 a, 906 b, 906 c, . . . and the tank 929,the synthetic resin materials are stored which have been sortedaccording to the heat values of p₁, p₂, p₃, . . . (kcal/kg) and n(kcal/kg), respectively. These resin materials are then mixed to preparea composite resin material for blowing into a blast furnace or ametallurgical furnace as a substitute for coke. In this instance, thesynthetic resin materials should be mixed such that the heat value ofthe resulting mixture is made greater than that of coke generallytypified for practical operation. In order to ensure this requirement,the mixing is automatically performed by means of weighing/cuttingapparatus 907 and 929 a and in accordance with the instructions of acontrol counter 930 so that the following equations (15) and (16) areobserved.

{(p ₁ x ₁ +p ₂ x ₂ +p ₃ x ₃+. . . )/100+Q  (15)

(x ₁ +x ₂ +x ₃+. . . )+y=100  (16)

where p₁, p₂, p₃, . . . are the heat values of granular synthetic resinmaterials (kcal/kg), x₁, x₂, x₃, . . . are the proportions of thegranular synthetic resin materials (% by weight), n is the heat value ofa composite synthetic resin material containing resin cuts only(kcal/kg), y is the proportion of a composite synthetic resin materialcontaining resin cuts, and Q is the heat value of coke typified forpractical operation.

Both the granular synthetic resin material 901 a′ and the cut syntheticresin material 901 b″ thus prepared are admixed by use of a mixer 931.

The resultant composite synthetic resin material, composed of a resinmaterial of a smaller heat value and that of a larger heat value, isconveyed to pneumatic equipment 932 and blown into the blast furnace 934out of the tuyrene 935 via a blow pipe 934. In the pneumatic equipment,a synthetic resin material 901 c is pneumatically fed into a servicetank 932 a, a storage tank 932 b, a pressure equalization tank 932 c anda blowing tank 932 d in that order and eventually blown into the furnace934 by the action of air pressure applied by an accumulator 932 e.

When placed in a storage yard and exposed to rainfall, film-shapedsynthetic resin materials 901 a and solid synthetic resin materials 901b involve increased moisture content, apparently causing decreased heatvalue. Rises in moisture content are remarkably true of urethanes andpaper-included resin materials. As for the film-shaped resin materials901 a, any moisture content can be removed at a step ofmelting/solidification/granulation. However, the solid resins 901 b areconveyed as wetted from a primary crushing step to a step where they arepneumatically fed for blowing into a blast furnace with the result thattransport faults such as clogged pipe frequently take place somewherebetween both of the process steps. In addition, the solid resin materialincludes halogen-containing resins such as polyvinyl chloride and thelike, thus posing the problem that halogen is corrosive with respect ofthe associated equipment. The halogen also tends to react with H₂O undercertain conditions, particularly in waste gas recovering conduits,eventually giving rise to objectionable acid corrosion.

With those problems in view, the present inventors have made furtherstudies and found that composite synthetic resin materials should have amoisture content of not larger than 8% by weight and that the content ofhalogen in such a synthetic resin material should not exceed 3% byweight. The present invention has been contrived to meet with theserequirements. More advantageously, the moisture and halogen contentsshould be simultaneously satisfied as specified above.

Examples

The present invention will be further described in more detail withreference to the following examples. Tests indicated below wereconducted with use of the quality determination method and the heatvalue evaluation method, both methods being shown in FIG. 42, and theequipment layout for blast furnace operating conditions shown in FIG.43. In the case with Example 4, a vertical testing furnace modeled aftera blast furnace was used in place of the blast furnace of FIG. 43.

Example 1

In a practical blast furnace, the present invention was tested under theblast furnace operating conditions and synthetic resin material blowingconditions shown in Table 32. Film-shaped resin materials 901 a andsolid resin materials 901 b were subjected to quality determination bymeans of the quality determining apparatus 902 a and 902 b. The resinmaterials 901 a and 901 b were free from impurities such as paper,fabric and metal. Quality determination revealed that the film-shapedresin material 901 a was composed of polyethylene and polyacetal, andthe solid resin material 901 b was made up of polyurethane and PET. Theheat values of such resins were identified from the commonly known datato be 11,000 kcal/kg for polyethylene, 3,000 kcal/kg for polyacetal,6,500 kcal/kg for polyurethane and 5,000 kcal/kg for PET. After qualitydetermination, the resin materials were treated as given below.

The polyethylene and polyacetal of the film-shaped resin material 901 awere separately treated through the melting/solidifying/granulatingapparatus 909 into granular resins 901 a′ which were thereafter storedin the heat volume-sorted hoppers 906 a and 906 b.

On the other hand, the polyurethane and PET of the solid resin material901 b were determined in regard to their heat values and storedrespectively in the heat value-sorted hoppers 925 a, 925 e, followed bycutting of both resins in a proportion of 60.0% by weight to 40.0% byweight and by subsequent mixing of the same. The heat value of the mixedcut resin material was determined to be 5,900 kcal/kg. This resinmaterial was then sieved, separated and adjusted in its particlediameter to be below 6 mm, after which it was stored in the cutsynthetic resin material storage tank 929.

Next, 55.0% by weight of the polyethylene and 20.0% by weight of thepolyacetal contained in the granular resin material 901 a′ were admixedin a mixer 931 with 25.0% by weight of the cut resin material in whichthe polyurethane and PET had been mixed with each other so that acomposite synthetic resin material was prepared and then pneumaticallyfed into the service tank 932 e. The composite synthetic resin materialso obtained was determined to be 8,125 kcal/kg with regard to its heatvalue.

The composite synthetic resin material 901 c thus pretreated was blowninto the blast furnace by means of the pneumatic equipment 932. Theproportions of the resins in such resin material are shown in Table 33as measured upon lapse of time after preparation of the resin material.

TABLE 32 Blast furnace Iron production 9000 t/d operating conditionsCoke rate 447 kg/t-pig Blast volume 7260 Nm³/min Oxygen enrichment ratio4 vol. % Blast temperature 1000° C. Blowing conditions Blow amount ofsynthetic resin 60 kg/min material Blow amount of pneumatic gas 1200Nm³/min Type of pneumatic gas Air

TABLE 33 Calorific value (Kcal/Kg) Proportion (wt. %) Polypropylene11000 55 Polyurethane 6500 15 PET 5000 10 Polyacetal 3000 20 Compositesynthetic 8125 100 resin material

The above operation of Example 1 was continuously run for 2 consecutivedays. Noticeably excellent results have been produced which arefavorably comparable to the results obtained from a usual blast furnaceoperation where no synthetic resin material is used.

Example 2

Also in a practical blast furnace, the present invention was testedunder the blast furnace operating conditions and synthetic resinmaterial blowing conditions shown in Table 32. Film-shaped resinmaterials 901 a and solid resin materials 901 b were subjected toquality determination by means of the quality determining apparatus 902a and 902 b.

The film-shaped resin material 901 a was free from impurities such aspaper, fabric and metal and was of a polypropylene formation. The heatvalue of such resin was determined to be 11,000 kcal/kg from thecommonly known data. After being subjected tomelting/solidification/granulation treatment, the resin material wassieved, separated and adjusted in its particle diameter to be less than6 mm so that a granular synthetic resin material 901 e was prepared andstored in the heat value-sorted hopper 907.

The solid resin material 901 b was found to be composed of polyurethane,ABS and PET. The polyurethane was determined to be 6,500 kcal/kg in itsheat value in light of the known data and then stored in the heatvalue-sorted hopper 925 a. It was observed that upon secondary crushingand subsequent treatment with the separator 924, ABS and PET even in theform of crushed resin materials 901 b′ were involved in such inclusionsas paper and fabric. Prior to storage in the heat value-sorted hopper925 b, 925 c such resins were sampled and measured with respect to theirheat values according to JISM 8814. The paper-included ABS showed a heatvalue of 4,500 kcal/kg and the fabric-included PET of 3,500 kcal/kg.These resins were stored in the hoppers 925 b, 925 c. From theirrespective hoppers, the polyurethane, paper-included ABS andfabric-included PET were taken out in a proportion of 33.3% by weight,22.2% by weight and 44.5% by weight, respectively, so as to prepare acomposite cut synthetic resin material 901 b′ of 4,722 kcal/kg in heatvalue. This resin material after being sieved and separated was adjustedin its cut diameter to be below 6 mm and stored in the resin materialtank 929.

Thereafter, a granular polypropylene material 901 a″ was mixed in anamount of 55.0% by weight with 45.0% by weight of a cut resin material901 b″ composed of a paper-included ABS and a fabric-included PET, andthe resultant synthetic resin material 901 c was pneumatically fed intothe service tank 932 a. The heat value of the resin material 901 c was8,175kcal/kg.

The synthetic resin material 901 c derived from pretreatment as statedabove was blown into the furnace 934 by means of the pneumatic equipment932. The proportion of the resins in the resin material 901 c wascounted as shown in Table 34.

TABLE 34 Calorific value (Kcal/Kg) Proportion (wt. %) Polypropylene11000 55 Polyurethane 6500 15 Paper-included ABS 4500 10 Fabric-includedPET 3500 20 Composite synthetic 8175 100 resin material

Those resin portions of a particle diameter or cut diameter in the rangeof 6 to 35 mm were charged together with coke out of the furnace top.Those resin portions having a particle diameter or cut diameter greaterthan 35 mm were returned back to the cutting apparatus 903 or theprimary crusher 920 for reuse.

The above operation of Example 2 was continuously run for 2 consecutivedays. Noticeably excellent results have been produced which arefavorably comparable to the results obtained from a usual blast furnaceoperation with use of no synthetic resin material.

Example 3

In a practical blast furnace, the present invention was tested under theblast furnace operating conditions and synthetic resin material blowingconditions shown in Table 32. All of the lots tested here were inducedfrom solid synthetic resin materials 901 b. One lot of them wasconsiderably wetted due to rainfall, and analysis reveald that the watercontent was as high as about 40% by weight. Since this wet lot wasconveyed as it was into process steps subsequently to the primarycrusher 920, the associated conduits and tanks might undergo clogging.Thus, separate drying was done up to a water content of 5% by weight orbelow.

Each of the lots was treated as determined, and by inspection on thesynthetic resin material determining apparatus 902 b, the lot was foundto be composed of polyprolylene, polyurethane, paper-included ABS andfabric-included PET. The paper-included ABS was subjected to drying todrop the water content. The resins were mixed as shown in Table 35, andthe heat value of the composite synthetic resin material 901 c was setat 8,375 kcal/kg and the moisture content at 0.9% by weight.

The composite synthetic resin material 901 c was pretreated as statedabove, and those resin portions of less than 6 mm in cut diameter wereblown into the furnace 934 by use of the pneumatic equipment 932.

TABLE 35 Calorific value Proportion Moisture content (Kcal/Kg)¹⁾ (wt.%)²⁾ (wt. %)²⁾ Polypropylene 11000 50 0.1 Polyurethane 6500 20 0.2Paper-included ABS 4500 15 £5 Fabric-included PET 3500 10 0.2 Compositesynthetic 8375 100 0.9 resin material ¹⁾Free from moisture ²⁾Afterremoval of rainwater by drying

The above operation of Example 3 was continuously run for 2 consecutivedays. Noticeably excellent results have been produced which arefavorably comparable to the results obtained from a usual blast furnaceoperation where no synthetic resin material is used.

Example 40

Testing was directed to blowing into a metallurgical furnace ofhalogen-containing synthetic resin materials such as polyvinyl chloride(Examples 4-1 to 4-3). A combustion testing apparatus modeled after theblast furnace of FIG. 43 was put to use here. Synthetic resin materialswere pretreated in the same manner as in Example 1 and with the use ofthe equipment of FIG. 2. However, all of the resin materials blown intothe furnace were those previously identified in respect of theirqualities. Inclusions such as paper, fabric and metal were absent, andwetting was free.

Table 36 illustrates the test furnace operating conditions and resinmaterial blowing conditions for testing of the halogen-containing resinmaterials. The tests consisted of Examples 4-1 to 4-3, and Example 4-1incorporated polyethylene and polyvinyl fluoride, Example 4-2 didpolyethylene and polyvinyl chloride, and Example 4-3 did polyethyleneand a bromine-containing printed circuit board. The halogen contentswere set at 3% by weight.

Table 37 lists the details of resin material blowing conditions forExamples 4-1 to 4-3 along with the heat values of composite resinmaterials. The resin materials were all of a solid type with a cutdiameter of not larger than 6 mm.

TABLE 36 Conditions of testing Blast temperature 1200° C. furnace Oxygenconcentration 21 vol. % Tuyere nose gas flow velocity 149 m/sec Cokediameter 25 ˜ 40 mm Blowing of synthetic Blow amount (polyethylene +62.5 kg/min resin material halogen-containing synthetic resin) Syntheticresin material diameter below 6 mm

TABLE 37 Example 4-1 Example 4-2 Example 4-3 Blowing ofHalogen-containing Polyvinyl chloride Polyvinyl fluoride Printed-wiringsynthetic synthetic resin material board resin Breakdown of syntheticPolyethylene Polyethylene Polyethylene materials resin material (kg/min)59.2 57.9 35.7 Polyvinyl Polyvinyl fluoride Printed-wiring Chlorideboard 3.3 4.6 26.8 [Total] [62.5] [62.5] [62.5] Halogen atom Cl F BrHalogen content in 56 wt. % 41 wt. % 7 wt. % synthetic resin materialAmount of blown 1.8 kg/min 1.9 kg/min 1.9 kg/min halogen Heat value 4300Kcal/Kg 1900 Kcal/Kg 2400 Kcal/g

Analysis of waste gases having come out of the test furnace revealedhydrogen chloride, hydrogen fluoride and hydrogen bromide which hadinvited nothing hazardous to environmental protection and also acidcorrosion of the associated equipment. Besides, sufficient iron meltingwas attainable as desired.

The following facets have now been found from the results of theseExamples.

[1] Though having hitherto been useless for blowing into a blastfurnace, synthetic resin materials of a smaller heat value areapplicable to adequate operation of such furnace so long as they arecapable of maintaining a heat value at a given level by incorporationwith similar resin materials of a larger heat value.

[2] For blowing into a blast furnace, waste synthetic resin materialscan be substituted for coke when their mixing proportions are suitablyselected in terms of heat values as parameters. Such a resin material isalso useful as a reducing agent for iron ore. Namely, the wastesynthetic resin materials can be recycled as starting materials forblast furnace operation.

[3] When decreased in their water contents to be less than about 8% byweight, composite synthetic resin materials can be employed withoutclogged pneumatic pipes caused during blowing operation in a blastfurnace.

[4] When their halogen contents are so selected as to be not more thanabout 3% by weight, composite synthetic resin materials can be blowninto a blast furnace without involvement in acid corrosion of thecorresponding equipment and also in environmental pollution under theinfluence of halogenated hydrogens by-produced as waste furnace gases.

With the present invention constructed as specified above, syntheticresin materials of a smaller heat value can be increased up to a desiredlevel of heat values by incorporation with those of a larger heat value.The smaller heat value-resin materials are also effective as a reducingagent. Thus, such smaller heat value-resin materials are acceptable forblowing into a blast furnace as in the case with the larger heatvalue-resin materials in common use, and hence, are useful as asubstitue fuel for coke. In addition and advantageously, the smallerheat value-resin materials hitherto disposed by incineration andreclamation can be effectively utilized with consequential contributionto enhanced environmental protection. As a result, the method of thepresent invention of blowing synthetic resin materials into ametallurgical furnace is of great industrial significance.

Embodiment 10

A first method is directed to the operation of blowing synthetic resinmaterials into a blast furnace, wherein use was made of a coarselygrained synthetic resin material resulting from adding 3 to 20% byweight of a fine resin material having a maximum particle diametersmaller than 2 mm relative to the total weight of a coarse resinmaterial containing more than 50% by weight of particles of a particlediameter larger than 10 mm.

A second method is directed to the operation of blowing synthetic resinmaterials into a blast furnace, wherein use was made of a coarselygrained synthetic resin material resulting from adding 3 to 20% byweight of a reduced grained iron ore having a maximum particle diametersmaller than 2 mm and a pre-reduction ratio of 50 to 90% relative to thetotal weight of a coarse resin material containing more than 50% byweight of particles of a particle diameter larger than 10 mm.

A third method is directed to the operation of blowing synthetic resinmaterials into a blast furnace, wherein use was made of a coarselygrained synthetic resin material resulting from adding 2 to 20% byweight of a finely grained coal having a maximum particle diametersmaller than 2 mm relative to the total weight of a coarse resinmaterial containing more than 50% by weight of particles of a particlediameter larger than 10 mm.

A fourth method is directed to the operation of blowing synthetic resinmaterials into a blast furnace, wherein use was made of a coarselygrained synthetic resin material resulting from adding 1 to 20% byweight of a paraffin having a maximum particle diameter smaller than 2mm relative to the total weight of a coarse resin material containingmore than 50% by weight of particles of a particle diameter larger than10 mm.

In the practice of the present invention, the coarsely grained syntheticresin material is specified to be such containing more than 50% byweight of particles of a particle diameter larger than 10 mm. This isattributable to the fact that when the particle diameter is smaller than10 mm, or when the content of particles having a particle diameterlarger or smaller than 10 mm is below 50% by weight, the associatedpipes cannot be protected to a noticeable extent against abrasion thatwould be caused during operation of a blast furnace. However, particlediameters beyond 30 mm are rather excessive and hence unfeasible withparticular regard to the diameter of pipings used.

In the first method, maximum particle diameters smaller than 2 mm asconcerns the fine resin material render the resulting particles lessangularly or virtually spherical, eventually decreasing abrasion of themating pipes that would arise from pneumatic feeding of such resinmaterial. Addition of 3 to 20% by weight of the fine resin material tothe coarse resin material enables the pipes to be cushioned againstimpact fatigue tending to occur by the action of the coarse resinmaterial, thus protecting the pipes from becoming abrasive.

The proportion of the fine resin material should not depart from theabove specified range. Below 3% by weight is less effective to cushionthe pipes against impact exerted by the coarse resin material. Above 20%by weight is extremely costly to prepare a fine resin material.

The second method is concerned with blowing a coarsely grained syntheticresin material into a blast furnace, characterized in that a coarselygrained synthetic resin material is used which results from adding 3 to20% by weight of a reduced grained iron ore having a maximum particlediameter smaller than 2 mm and a pre-reduction ratio of 50 to 90%relative to the total weight of a coarse resin material containing morethan 50% by weight of particles of a particle diameter larger than 10mm. Such iron ore, like the resin material, should be smaller than 2 mmin its maximal particle diameter so that the iron ore becomes lessangular and rather spherical. Moreover, the reduced iron ore derived bypre-reduction is of the same material as in the corresponding pipes and,upon addition in an amount of 3 to 20% by weight, is capable ofcushioning impact applied by the coarse resin material during pneumaticfeeding thereof onto the pipes, thereby preventing the latter from wear.The pre-reduction ratio of the reduced grained iron ore should rangefrom 50 to 90%. Less than 50% leads to an excessive amount of unreducediron ore grains, resulting in a large deviation from the material of thepipes and hence failing to sufficiently protect the pipes againstabrasion. Conversely, more than 90% produces a reduced grained iron oreonly in an expensive manner.

The reduced sintered ore should also be added in the above specifiedrange of proportions. Below 3% by weight is less effective in cushioningthe pipes against impact exerted by the coarse resin material. Above 20%by weight leads to increased cost in producing a reduced sintered ore.

With respect to the third method, the finely grained coal is lessangular and virtually spherical when its maximum particle diameter issmaller than 2 mm as is in the resin material, and hence, is lessabrasive relative to the associated pipings during pneumatic feedingthereof. When added in an amount of 2 to 20% by weight, such coalprotects the pipes against impact abrasion exerted by the coarse resinmaterial.

The proportion of the finely grained coal should be met as specifiedhereinabove. Below 2% by weight is less effective for cushioning thepipes against impact induced from the coarse resin material, whereasabove 20% by weight is responsible for costly preparation of a finelygrained coal.

Turning to the fourth method, the paraffin is less angular and ratherspherical when its maximum particle diameter is smaller than 2 mm as isin the resin material, and hence, is less abrasive relative to theassociated pipes during pneumatic feeding thereof. When added in anamount of 1 to 20% by weight, the paraffin protects the pipes fromimpact wear caused by the coarse resin material.

The proportion of the paraffin should be held in the above specifiedrange. Less than 1% by weight is not sufficient to cushion the pipesagainst impact induced from the coarse resin material, and more than 20%by weight is costly to prepare a paraffin.

Certain preferred forms of the method according to the present inventionwill now be described with reference to the drawings.

FIG. 44 is a flow diagram taken to explain the method of the presentinvention. Designated at 1001 is a first hopper for receiving a coarselygrained synthetic resin, at 1002 a cutting apparatus for cutting aconstant quantity of the resin accommodated in the first hopper, at 1003a second hopper for receiving a finely grained synthetic resin, areduced grained iron ore and the like that are used to prevent pipesagainst abrasion caused by pneumatic transport of the coarse resin andat 1004 a cutting apparatus for cutting a constant quantity of each ofthe abrasion-preventing materials from the second hopper. A mixer isdesignated at 1005 for uniformly intermixing the coarse resin taken outof the cutting apparatus 1002 and the abrasion-preventing materialstaken out of the cutting apparatus 1004. A drum mixer, for example, maybe used as that mixer. Designated at 1006 is a blowing apparatus, at1007 an air supply conduit, at 1008 a blast furnace and at 1009 blowinglances.

A first form of method is illustrated below.

Accommodated in the first hopper 1001 is a coarsely grained syntheticresin having a maximal particle diameter of 30 mm. Through the cuttingapparatus 1002, such coarse resin is taken out in an amount desired tobe blown into the blast furnace. In the second hopper 1003, a finelygrained synthetic resin is accommodated which has a maximal particlediameter smaller than 2 mm. The fine resin is taken out through thecutting apparatus 1004 in an amount preset with respect to the amount ofthe coarse resin to be taken out. The amount of the fine resin to betaken out is set to range from 3 to 20% by weight.

The coarse and fine resins so taken out are conveyed into the mixer 1005where they are uniformly mixed with each other. The resultant mixture istransferred into the blowing apparatus 1006, from which the mixture isthen pneumatically transported via the air supply conduit 1007 and blownthrough the blowing lances 1009 into the blast furnace 1008.

A second form of method is illustrated below.

The same coarse resin as in the first form of method is accommodated inthe first hopper 1001 and cut out of the cutting apparatus 1002 in anamount needed to be blown in. In the second hopper 1003, a reducedgrained iron ore is accommodated which has a maximal particle diametersmaller than 2 mm and a pre-reduction ratio of 50 to 90%. The iron oreis taken out through the cutting apparatus 1004 in an amount preset withrespect to the amount of the coarse resin to be taken out. The amount ofthe iron ore to be taken out is set to range from 3 to 20% by weight.

Subsequent process steps are as in the case with the first form ofmethod.

A third form of method is illustrated below.

The same coarse resin as in the first form of method is accommodated inthe first hopper 1001 and cut out of the cutting apparatus 1002 in anamount needed to be blown in. In the second hopper 1003, a finelygrained coal is accommodated which has a maximal particle diametersmaller than 2 mm. The coal is taken out through the cutting apparatus1004 in an amount preset with respect to the amount of the coarse resinto be taken out. The amount of the coal to be taken out is set to rangefrom 2 to 20% by weight.

Subsequent process steps are as in the case with the first form ofmethod.

A fourth form of method is illustrated below.

The same coarse resin as in the first form of method is accommodated inthe first hopper 1001 and cut out of the cutting apparatus 1002 in anamount needed to be blown in. In the second hopper 1003, a paraffin isaccommodated which has a maximal particle diameter smaller than 2 mm.The paraffin is taken out through the cutting apparatus 1004 in anamount preset with respect to the amount of the coarse resin to be takenout. The amount of the paraffin to be taken out is set to range from 1to 20% by weight.

The fine synthetic resin, reduced grained iron ore and paraffin wereexemplified as the abrasion-preventing materials, Paper, woodmeal andfabric are also suitably useful as the abrasion-preventing materials inthe present invention so long as they are by nature soft and generallyspherical in shape.

Examples

Testing was run to blow into a blast furnace a coarsely grained resinhaving a maximum particle diameter of 30 mm under a set of operatingconditions indicated below. As for a comparative example wherein anabrasion-preventing material had been omitted, and the first to fourthforms of method, checking was made of whether air supply conduits hadinvolved holes. Each of the tests run for one month.

[Operating Conditions]

iron production: 9,000 t/d

blast amount: 7,260 Nm³/min

blast temperature: 1,000° C.

coke volume: 447 kg/t·pig

The test results are shown in Table 38. The comparative example causedholes twice over in the conduit, entailing shutdown for 10 hours. Thefirst to fourth forms of method have proved free from holes and henceconducive to desirable effects flowing from addition ofabrasion-preventing materials.

TABLE 38 Present Present Present Present Comparative ex. Invention 1Invention 2 Invention 3 Invention 4 Coarse-grained Particle diameterrange (mm) 10-30:60% 10-30:60% 10-30:60% 10-30:60% 10-30:60% syntheticresin Blow amount (kg/min) 62.5 51.3 51.3 51.3 51.3 Fine-grained Maximumparticle diameter (mm)  2 synthetic resin Proportion (%) 18 Reduced ironore Maximum particle diameter (mm)  2 particle Pre-reducbon ratio (%) 75Proportion (%) 18 Finely divided Maximum particle diameter (mm)  2 coalProportion (%) 18 Paraffin Maximum particle diameter (mm)  2 Proportion(%) 18 Shutdown due to piping replacement (hr/month) 10  0  0  0  0

Embodiment 11

Gases generated in a blast furnace are discharged out of a top of thefurnace and at an average flow rate usually in the order of 0.9 to 1.2m/sec. In charging a waste synthetic resin material into the furnace outof the top thereof, the resin material when sized to be smaller than acertain level gets flown outside the furnace because of a gas streamemitted upwardly from the furnace top. Hence, it may be thought that thewaste resin material is so prepared as to exceed a certain critical sizeto withstand flying against the gas stream and to initiate fluidization.Use of a waste resin material meeting such requirement, however, invitesnot only extensive remolding of the existing charging apparatus andimpossible uniform mixing with other starting materials to be charged,but also low combustion, thus impairing stable blast furnace operation.

For that reason, it is preferred that waste resin materials be limitedto a certain range of sizes.

To clear up those problems, several sorts of means are consideredfeasible. That is to say, [1] a waste resin material is mixed with adifferent starting material having a by far greater bulk density thandoes the former, [2] the particle diameter of such great bulkdensity-starting material is rendered relatively small and hence highlyresistant to a gas stream, coupled with decreased rate of gas flow, and[3] the resulting mixture is charged into a region on a stock line of ablast furnace (uppermost surface of a layer of starting materialscharged in the furnace), which region is maintained in a minimized rateof gas flow, whereby a small bulk density-resin material charged out ofthe furnace top is hardly flown outside under the influence of a gasstream.

Small-grained sintered ore has been studied as suited for [1] and [2]above. A sintered ore for use as a starting material in a blast furnacehas a bulk density of 2.87 g/cm³ that is by far higher than that of awaste resin material, 0.3 g/cm³. A sintered ore is used with a particlediameter within a given range, and those ore portions of a smallerparticle diameter are sent as “return ore” back to a sintering stage.The particle diameters of return ores are variable with the interofficespecifications of steel mills. A return ore leads to delayed rate of gasflow and hence acts to diminish flown waste resin material. Thus, noparticular restriction is imposed upon the maximum particle diameter ofa small-grained sintered ore used in combination with a waste resinmaterial. On the other hand, the minimum particle diameter of asmall-grained sintered ore used for that purpose should be chosen tosuch a size that the sintered ore itself is not flown due to an upwardlyemitting furnace gas stream. With a 4,000 m3-capacity blast furnacepostulated as a usual blast furnace, the particle diameter of a sinterediron ore is calculated to be 1.5 mm, which particular diameter is onerequired for the iron ore to fluidize at a higher rate than the rate ofgas flow on a stock line in the furnace. Namely, a sintered ore of aparticle diameter smaller than 1.5 mm gets flown outside at the furnacetop, and hence, should be larger than 1.5 mm in particle diameter formixing with a waste resin material and then for charging into thefurnace out of the top thereof.

The advantages noted below have been gained upon use of a return ore asa small-grained sintered ore for incorporation with a waste resinmaterial.

(i) The small-grained sintered ore is useful as it is, as a startingmaterial for blast furnace operation, without the need for return to asintering stage, and (ii) such sintered ore is heated and reducedthrough combustion of a waste resin material, and therefore, saved cokevolume is also attainable.

In regard to those standpoints, the present inventors have conducted thefollowing tests with the results given below.

One test was made to grasp the effects which the size of a waste resinmaterial produces on the amount thereof having been flown outside a topof a blast furnace owing to a gas stream emitted from the furnace. Byuse of a blast furnace having an iron production capacity of 10,000t/day, a mixture of a waste resin material and a small-grained sinteredore was charged via a distributing chute from a bell-free chargingapparatus located at a top of the furnace. Charging was effected with atarget region defined on a stock line (internal radius of the furnace:5.5 m) and on a concentric circle having a radius of 3.5 m as measuredaround the centerline of the furnace.

In this test, with the particle diameter d_(ss) of a small-grainedsintered ore set for convenience at 5 mm as an upper limit, use was madeof a sintered ore having a d_(ss) of 1.5 to 5 mm and a particle sizedistribution of 3.6 mm in average particle diameter, and of a wasteresin material having a size (long diameter) within a range of 25 to 150mm and divided into four different levels (25, 30, 100 and 150 mm). Whenthe weight Wp of the waste resin material and the weight Wss of thesmall-grained sintered ore were assigned, the proportion α of the wasteresin material was expressed as α=Wp/(Wp+Wss). Examination was made atfour levels (0.1, 0.2, 0.3 and 0.4) in a range of 0.1 to 0.4. The amountof the waste resin material flown was measured from the amount of suchresin material collected on a gas filter, and the fly ratio was definedby the equation, {(fly weight of waste resin material)/(charge weight ofwaste resin material)}×100(%).

The test results obtained above are shown in FIG. 48 in which therelationship between the long diameter dp of and the fly ratio f of thewaste resin material is plotted against each varying proportion α of thewaste resin material. As is clear from FIG. 48, the smaller the longdiameter of the waste resin material is, the fly ratio f or{(flyweight/charge weight) ×100 (%)} becomes higher. Large diameterssmaller than 50 mm show a sharp decline in fly ratio, and this meansthat the long diameter of the waste resin material should preferablyexceed 50 mm. Long diameters larger than 100 mm, however, areresponsible for poor combustion. Accordingly, the long diameter of thewaste resin material should preferably be in the range of 50 to 100 mm.

Next, the following description is directed to the effects which thecharge region of a mixture of a waste resin material and a small-grainedsintered ore on a stock line brings about on the fly ratio of the wasteresin material.

With use of the aforementioned furnace, the relationship was examinedbetween the region where the above mixture was charged radially of thefurnace and the fly ratio f of the waste resin material under theconditions with a long diameter dp of 50 to 100 mm of and an averageparticle diameter d_(ss) mean of 3.0 to 4.0 of the small-grainedsintered ore, and with a proportion α of 0.2 of the waste resinmaterial. The test results are shown in FIG. 49.

The results of FIG. 49 show that when the above mixture was charged intoa localized region of 30 to 80% directed radially toward an innerperipheral wall of the furnace as measured around the centerlinethereof, the fly ratio f of the waste resin material becomes smaller.Charging in a localized region of 40 to 70% is more effective for adecline in fly ratio. Thus, waste resin materials are useful with utmostefficiency. The localized region noted here is a circular region havinga width of 2.5 m defined around the furnace centerline.

The larger the size is, the waste resin material is less reactive andless compatible with the small-grained sintered ore in the furnace.Stable blast furnace operation requires for a waste resin material to becombustive and distributive as uniformly as possible in the furnace.Greater long diameters of the waste resin material than 120 mm lead toinsufficient uniformity in mixing with a small-grained sintered ore.Besides, use of a waste resin material in a large amount results indeteriorated stability of blast furnace operation. Smaller longdiameters than 100 mm should be observed to obviate those problems.

With the foreging findings taken in view, it is preferred that a wastesynthetic resin material to be charged into a blast furnace out of a topthereof have a long diameter of 50 to 100 mm, and a small-grainedsintered ore to be charged in combination therewith have a particlediameter up to 100 mm.

The present invention bases its completion on the above findings. Afirst method of the invention wherein a waste resin material is chargedinto a blast furnace out of a top thereof, characterized by the steps ofpreparing a waste resin material as a starting material for blastfurnace operation, of preparing a small-grained sintered ore as astarting material for blast furnace operation, of mixing the resinmaterial and sintered ore of the first two steps to thereby make up amixture thereof, and of feeding such mixture into a charging apparatusdisposed at the furnace top and then charging such mixture from thecharging apparatus onto a surface of a layer of previously chargedstarting materials and into a localized region defined in anintermediate portion between a centerline of and an inner wall of thefurnace.

A second method is subordinate to the first method and is characterizedin that the waste resin material has a long diameter of 50 to 100 mm,the sintered ore has a particle diameter of not smaller than 1.5 mm, andthe above intermediate portion between the furnace centerline and thefurnace wall is a region defined in a range of 30 to 80% relative to aninternal diameter of the furnace and directed from the furnacecenterline toward the furnace wall.

The present invention will be further described with reference to thedrawings.

FIG. 45 is a schematic view, taken vertically cross-sectinally, of apreferred form of the method according to the present invention, whereindetails as regards a top of a blast furnace are illustrated. A mixture1102 of a waste synthetic resin material and a small-grained sinteredore is shown charged out of a furnace top 1101 onto a surface of an orelayer 1103. After being crushed and sieved into a given size, the wasteresin material and sintered ore are mixed in a mixer (not shown) andthen charged from a distributing apparatus 1104 located at the furnacetop 1101.

The waste resin material to be used is from 50 to 100 mm in longdiameter, and the sintered ore is 1.5 to 100 mm in particle diameter. Inthe illustrated method, the particle diameter of the sintered ore is setat 5 mm as an upper limit. However, the upper limit in particlediameters of a return ore obtainable during preparation of a sinteredore depends usually on the conditions set for producding the sinteredore. Such upper limit may be decided according to the maximum particlediameter of the return ore. In the practice of the present invention, nolimitation needs to be imposed on the upper limit in particle diametersof the sintered ore. The target region of charge is adjusted by means ofthe distributing chute 1104 and defined by an intermediate portionbetween the furnace centerline 1105 and the furnace wall 1106 (regiondefined in a range of 30 to 70% and directed radially from the furnacecenterline toward the furnace wall, this region being referred to hereinas “intermediate region”).

During adequate operation of a blast furnace, a rate of gas flow isoriginally lower in the intermediate region between the furnacecenterline and the furnace wall than in other regions within thefurnace. Those materials of small bulk densities such as a wastesynthetic resin material, therefore, may be charged into theintermediate region so that they are rendered less susceptible toflying. In addition, when the waste resin material is charged incombination with a small-grained sintered ore having a larger bulkdensity than the former, a rate of gas flow in the intermediate regionis made low by the action of the sintered ore with the result that thewaste resin material can be protected from flying. Low rates of gasflow, however, result in delayed ore reduction. Despite this adverseeffect, a waste resin material having a long diameter in the order of 50to 100 mm is more reactive than coke as a reducing agent from physicaland chemical standpoints. The carbon atom present in the waste resinmaterial is capable of activating a reaction of C+CO₂=2CO, thuscompensating for slow ore reduction.

In blast furnace operation performed under such conditions as with aconstant reacting weight of total solution loss, a waste resin materialwhen charged in the system produces decreased coke volume. Replacementof part of coke with a waste synthetic resin material also brings aboutdecreased reacting weight of coke in an equivalent weight of the wasteresin material having reacted to gasify, eventually preventing coke fromgetting deteriorated in respect of hot strength.

In FIG. 46, rates of gas flow distributed in a radial direction in thefurnace are compared with respect to the cases where a mixture of awaste synthetic resin material and a small-grained sintered ore wascharged out the furnace top and the cases where no such mixture wascharged. The ordinates shows, on a logarithmic scale, the ratio U/U_(o)between a rate of gas flow U on a stock line and a rate of gas flowU_(o) in an empty tower. Upon checking of FIG. 46, it can be observedthat the rate of gas flow is decreased to a markedly great extent in theintermediate region as a result of charging of a mixture of a wasteresin material and a small-grained sintered ore. Accordingly, suchmixture charged in the intermediate region prevents the small bulkdensity-waste resin material from becoming flown.

FIG. 47 shows a distribution curve concerning ore reduction ratiosrelative to the heights within the furnace as determined duringoperation in the cases where the above mixture was charged out of thefurnace top and where such mixture was omitted. As evidenced by FIG. 47,a mixture of a synthetic waste resin material and a small-grainedsintered ore when charged in the intermediate region promotes orereduction, and hence, the waste resin material acts effectively on oreto be reduced.

Examples

The present invention will be further described with reference toexamples and to FIG. 45.

By use of a blast furnace having an iron production capacity of 10,000t/day and a radius of 5.5 m on a stock line, a mixture 1102 of a wasteresin material and a small-grained sintered ore was charged out of thefurnace top 1104 through an auxiliary bell distributing chute 1105mounted on the top of the furnace. In such instance, the charge regionwas preset at a concentric circle having a radius of 3.5 was measuredaround the furnace centerline 1106.

Table 39 lists the long diameter dp of and the bulk density Pp of thewaste resin material used, the particle diameter d_(ss) of the sinteredore used, the proportion α of the waste resin material, the particlediameter dc of the coke used and the particle diameter ds of thesintered ore. Operation was run for 30 days with use of the waste resinmaterial in an amount of 130 t/day. In such case, the rate of gas flowU_(o) in an empty tower was 1.1 m/sec. For comparative purposes,operation (usual operation) was also run which was done in the samemanner as in the example of the present invention except that no wasteresin material was charged.

TABLE 39 Comparative Example example Waste synthetic resin Long particlediameter dp (mm) 100 — material Bulk density ρ p (g/cm³) 0.3 —Small-granular sintered Particle diameter dss (mm) 3 — ore Bulk densityρ ss (gcm³) 2.87 — Proportion 0.2 — Weight of waste synthetic resinmaterial/ (Weight of waste synthetic resin material + Weight ofsmall-granular synthetic resin material) Charged coke Particle diameterdc (mm) 50 50 Charged sintered ore Particle diameter ds (mm) 15 15

The operational results are shown in Table 40.

TABLE 40 Comparative Example example Productivity of molten pig iron(T/day) 10000  10000  Coke rate (kg/)  560  570 Melting temp. of pigiron (° C.) 1510 1510 Proportion of waste synthetic resin  10  0material (kg/molten pig iron T)

In the example of the present invention, the fly ratio f of the wasteresin material could be held at below 1.0% throughout the operation.Coke volume has been found improved in the operation of that example.Furthermore, stable furnace operation is also attainable with freedomfrom adverse effects produced on the operation and equipment.

What is claimed is:
 1. A method of blowing a synthetic resin materialinto a furnace, comprising: preparing a synthetic resin material havingan average specific surface area of at least 50 m²/kg; and blowing saidsynthetic resin material from tuyeres of a shaft furnace for ironmaking.2. A method of blowing a synthetic resin material into a furnace,comprising: preparing a synthetic resin material containing at least 5wt. % particles having a particle diameter of up to 1 mm and having anaverage specific surface area of at least 25 m²/kg; and blowing saidsynthetic resin material from tuyeres of a shaft furnace for ironmaking.3. A method of blowing a synthetic resin material into a furnace,comprising: preparing a synthetic resin material containing at least 3wt. % particles of a foaming substance and having an average specificsurface area of at least 20 m²/kg; and blowing said synthetic resinmaterial from tuyeres of a shaft furnace for ironmaking.
 4. A method ofblowing a synthetic resin material into a furnace, comprising: (a)determining the heat value of a synthetic resin material from the resultof a quality determination of the material when it is possible todetermine the quality of the synthetic resin material and mixing ofimpurities is not observed; (b) determining the heat value of asynthetic resin material by measuring by a measuring method when it ispossible to determine the quality of the synthetic resin material andmixing of impurities is observed; (c) determining the heat value of asynthetic resin material by measuring by a measuring method when it isimpossible to determine the quality of the synthetic resin material; (d)blending two or more kinds of synthetic resin materials based on theheat values for said two or more kinds of synthetic resin materials asdetermined in steps (a) to (c) so as to give a prescribed heat value ofa mixture comprising said two or more kinds of synthetic resinmaterials; and (e) blowing the blended synthetic resin materials fromstep (d) from tuyeres of the furnace.
 5. The method according to claim4, wherein said blended synthetic resin materials have a water contentof up to a prescribed value.
 6. The method according to claim 4, whereinsaid blended synthetic resin materials have a halogen content of up to aprescribed value.